Wrong Fuel?Petrol in Diesel FAQ’s 340


So here is a list of the wrong fuel questions I get asked on or before nearly every job!

If you have any questions, or need a fuel drain now, please contact us


Q; I drove my diesel car for 2 miles on petrol after I filled it up, then it just died on me. Will it need to be repaired ?

Answer; you didnt drive it for 2 miles on petrol whats more likely is you drove it for 2 miles with petrol in the tank. Once the petrol made its way through the low pressure sender pump, thru all the fuel lines, up to and through the filter (holds about a pint of fuel),  through the hoses to the high pressure pump, thru the pump, into the common rail resovoir, and finally into the high pressure lines into the combustion chamber, that’s normally the exact point that the engine stops turning, and in fact you will find you maybe got about 20 yards on petrol, which is the time it took for the engine to stall. The good news is, this isn’t as catastrophic as you might think and there is a simple, effective solution in a mobile fuel drain – a service we provide all over the country and we attend most call outs with 50 minutes, 24 hours a day. there are many different things that can happen with misfuelling, I have covered most of them below.

This is a typical case of a car that was driven for about 20 miles on the wrong fuel. We got the call out when the owner couldn’t start it in the morning, and then realised she had misfueled it the day before. This car had been drained from the tank and the fuel system flushed through, if you listen in the beginning the sound may be familiar to anybody who has tried to start a misfuelled car. But as the car starts, it quickly goes back to sounding normal. 99% of breakdowns caused by misfuel are this easy to fix. Humble apologies for the quality of this video, I took it on my phone, because it was the camera man’s day off!


Q; What does petrol do to a diesel car’s fuel system?

Answer: This  picture (below)  is the suction  line I use to remove wrong fuel . this was taken when doing a job that had 50 litres of petrol in a diesel mini, this was being taken from the fuel tank as the car had not been started. this hose is full of fuel, about 70% petrol, 30% diesel

Is wrong fuel harmfull

wrong fuel in hose

 

what does wrong fuel do to a car


This is a picture of the same hose, the car was a Diesel VW Polo, it has been fill’d with 90% petrol, and 10% diesel, the car had been left overnight after loosing power and being towed back to the customers house, the suction line was attached to the high pressure pump inlet, as you can see the fuel has gone black, this is becuase the petrol has desolved  rubber in the fuel lines,  this car sat for a day with a very strong mix of petrol, it had also been driven until failure, the dark colour is a mix of rubber and plastic that has dissolved in petrol (fuel hoses are made type specific to reduce costs for car manufacturers,i,e diesel for diesel hoses only and petrol in petrol hoses only), I would not expect this to have done the car any real harm over an 18 hour period, just a microscopic layer of fuel line has been stripped off from the inside, these lines are fairly thick so a short bit of contamination once is fine, if you do want to make a habit of misfuelling regularly and leaving the car sitting for days with the wrong fuel in it you will eventually need new fuel lines. and plastic fuel components


Q; What happens to the fuel once we take it out

Answer; at the end of the day (or during a very busy day), I unload all of my mixed fuel into 220 litres drums, at our garage, (a licence is required to store mixed fuel from the enviroment agency), the mix is collected every 7 to 10 days by a garage services company, these are the same guys who take away used engine oil, brake fluid etc.. from garages everywhere. the mixed fuel is batched seperetly and in-between me and all the other companys that offer this service, I would guess that there is between 50 to 200 thousand litres a week of mixed fuel “made” in the UK per week. – once it is batched up into viable quantities usually 28.000 litres (tanker load) it is refined in one of the main refinery’s using a distillation process – identical to the one used for making crude oil, the petrol diesel mix seperates at 60 – celsius, i,e the petrol fumes off, it is then condensed and seperated, from what I have heard this is done twice to get a proper result, I would assume that the mix would then go back into the supply chain and be used as it was originally intended!


Q; I put the wrong fuel in – have I damaged my car?

Answer; it is very unlikely that you have, pretty much 1 for 1 call outs I attend are back up and running again when drained, if you have not started your car, you will not have damaged it. if you have driven your car and it stalled, or would not re-start then the chances of any lasting damage are very slim, there’s a bit of a safety mechanism that works by defualt and it goes like “petrol will ruin your diesel car but your diesel car will not run on petrol long enough to get ruined, therefore, PETROL WILL NOT RUIN YOUR  DIESEL CAR”


Q; My car conked out, have I wrecked it?

Answer; no, as above “conking out” is your engines way of saying “I am not moving untill you get the wrong fuel out of me and the right fuel in”, I attend many “conk outs” “died” “made horrible noises” etc.. once they have been drained down , 20 litres of correct fuel put in -and the system fully purged upto the high pressure pump fuel inlet –  then , they all ran fine afterwards


Q; My car has a common rail pump, are you sure its going to be fine?

Answer; YES!, the vast majority of new diesel cars have sophisticated common rail pumps, we attend them day in, day out what I have written above applies specifically to common rails.


Q; Whats worse, diesel in petrol, or petrol in diesel?

Answer; the wrong fuel in varying quantities does different things, petrol in diesel will stall it, or depending on the mixture it might just still run, albeit sounding like a bag of spanners, – with reduced power  Diesel in a petrol car will make it lose power, and run flat. The worst case scenarios (and these are the WORST) are;

1) petrol in a diesel pump will eventually damage the pump (If you are unlucky enough to get a mix that just runs) , if you have not noticed it, and are completely oblivious to the car’s behaviour, you would also have to do a fair ammount of driving with a heavy foot, this would require a new common rail pump, piezo injectors and fuel lines,  the high pressure fuel pump which operates at 28 oddd thousand PSI of pressure and is a highley enginerd unit relies on diesel going thru it to provide lubrication, petrol does not lubricate, in fact it has “anti lubricating” properties, hence why petrol is good for cleaning out oil stains. what happens is the inner working of the high pressure pump start chaffing metal grinds on metal, this destroys the pump, then the metal chafe gets drawn thru to the piezo injectors and ruins them as well, now  before you go and sell a kidney to pay for a new diesel pump and injectors, please read the read the rest of these FAQ’s because full scale damage like this is very very rare.

2) diesel in petrol worst case scenario, the diesel will enter the cylinder and not burn, it will slide past the piston rings, into the oil sump and therefore the cars oil system, this will increase the oil level, to a point that could cause total engine failure, i.e mangled rods, bent pistons, complete block failure, or the thining of the oil can reduce lubrication to the engine and it could suffer from a full seizure/big end failure/ruined propshaft. Again this would not be an easy thing to do, the car would be very low on power and not running right, you would have to do a good bit of driving in it to achieve the above.


Q; Land rover/mercedes/bmw/audi etc all insist I bring it into the garage for a full drain and it will cost ££££££££££ what should I do?

Answer: main dealers and “tooth sucking garages” will sometimes take a misfuel case for all its worth. I have heard of people having misfueled cars collected by main dealers (these cars had not be started and were collected from the petrol station forecourt) and then the insurance company picks up a tab for 5 or 6 thousand pounds for parts that absoloutley dont need replaced, (and I would suspect never get replaced), this is all very well untill you lose your no claims bonus and when you trade your car in eventually you have to explain why it had so much major work when it was brand new,


Q; But the maindealer says I must bring it in otherwise the engine and pump will be ruined

Answer; I’ve got a fair bit to say about this, probably the most high profile example of manufacturers being totally inflexible  was the Icelandic volcano eruption, and the disruption to flights, it went like this, there was a small amount of ash detected in the air space, as a precuation the authorities asked Boeing & Rolls Royce what was a “safe” and what was an “unsafe” amount of ash for jet engines to fly in, the responce they got was “zero”, therefore all flying was banned. because none of the big engine makers would go out on a limb and come up with a “safe” level of ash everything came to a stop – (until the airlines started flying empty planes round in circles to prove that it was actually safe) Coming back to the automotive industry, the car manufacturers have a similar one policy fits all approach to wrong fuel in cars, , and that is certain things must get replaced after a fuel drain regardless of how much fuel was put in, for how long, or whether the car was driven. They win both ways, firstly they sell lots of parts and millions of hours of labour that wouldn’t otherwise be sold – and secondly they never have to deal with someone claiming warranty if there is any possibility of wrong fuel being used , they know that petrol in small temporary quantities won’t destroy a diesel engine, but they could never say it, because it they are wrong on just one car once… its would be one too many, that’s the manufacturers approach, and the main dealer network quickly caught up with the idea of turning it into a lucrative money spinner and starting milking customers and  insurance companies for thousands of pounds.


Q; I’ve read everything here but the stuff I read on the net and in car forums says otherwise, I still don’t know what to do?

Answer; I don’t blame you, I have seen the various discussions in forums on the net – it makes for scary reading if you have put petrol in a diesel car, you will find most of them are repeating threads from older posts, who have re-hashed threads from even older posts, that were written by armchair mechanics , the amount of conflicting information is also a clue as to the validity of the content,  there’s a lot of people talking a lot about something they know very little about, I do fuel drains, its my livelyhood, I do dozens every week, I have attended thousands of call outs, I have seen customers who I did fuel drains on after they had driven 10.0o0 20.000 and even 50.000 miles in their cars after putting the wrong fuel in and being drained, none of them had any damage that developed after the misfuel


Q; I’m in a hire car, should I call them and have them arrange something,

Answer. (I dont mind getting a legal letter on this one becuase I know it to be true) I received a call from a man in Canada on Tuesday, last week he was in the UK and misfuelld in a HERTZ rental car,  the forecourt attendant gave him my card, before he called me he had a quick look at the rental agreement, it  was quite clear that he was obliged to tell Hertz what had happened, so he did, and they sent the AA.  his card was then debited for £500 odd pounds, now the AA charge between £100 if they are quiet, to £230 if they are busy for a misfuel (no it is not covered by AA membership), so how did he end up paying £500?, Hertz called the AA and I assume got a whacking corporate discount and had the job done for 50 or 60 quid, they then put the boot in and charged the customer £500, he didnt have a choice in the matter because they had his card details, so if you are in a hire car you could either, call an independent mobile fuel drain company, or if that makes you uneasy – call the AA yourself , and pay for it yourself, you will save a small fortune.


Q; I have read all the above, now I think I will top up with the right fuel and chance my luck will that be ok?

Answer; hmm… I would always recommend a full fuel drain, not because I want your business but because petrol does not do any good in diesel engines, it can corrode rubber hoses and plastic seals that are fuel type specific (petrol and diesel behave differently on different materials, , so the car manufacturers use different plastics and rubber in the fuel system) , as much as I believe wrong fuel will not wreck a car, that is based upon the wrong fuel being taken out as soon as the mistake has been spotted, petrol in a diesel engine will eventually cause problems if not dealt with, but if you are driving an old knacker that will be scrapped when it fails its MOT that is due in a month then you might as well just risk it, but otherwise DRAIN DRAIN DRAIN


Q; Can I keep the wrong  fuel after you drain it, I want to use it in my lawnmower

Answer. there are easier ways of getting out of mowing the lawn other than ruining your lawn mower with a petrol diesel mix, maybe you should feign injury or concrete over the garden. Really misfuel is not worth trying to use, even if you think you have just put 80 quid of petrol in your range rover sport and assume you have a 99% petrol mix, allow me to elaborate.

when you drive a car your fuel sloshes around the tank, (even with baffles)  when it gets low and sloshes too much it draws air into the fuel system, this is what running out of fuel feels like, however the tank is not totally empty at this point, it merely cannot supply a constant flow of fuel without interruption,  but there is still around 5 to 10 litres in the tank, this changes the sums when you are calculating the “purity” of the mixed fuel, and you will actually have a fair bit more diesel in the mix than you thought you had, allot of people tell me that the “gauge said 3 miles left” and when Í’ve finished the drain and they fill back up they find they got 20 quid more in it that they ever had, and are genuinely surprises how big the tank actually is,  that said, if you really feel attached to it and have suitable containers and somewhere safe to store it, then I might just let you keep it, I will expect coffee, biscuits and perhaps a sandwich or two for the privilege


Q; Are there a lot of idiots/wallies/Muppets who misfuel like me?

Answer; I have met some of the nicest people doing fuel drains, in fact it has restored my faith in humanity! You most likely are not a Muppet, fuel filling pumps are very unstandard and there is no uniform colour coding of pumps, the AA released a snippet a few years ago that 300.000 people per year misfuel, I  think the true number is many times that, and the number of people who only misfuel by a pound or so is astonishing, people who lead busy lives or drive more than one car are more likely to misfuel, some older customers joke that maybe they have gone senile – and it doesn’t even occur to them that they have driven a petrol car for 40 years and just got a diesel fiesta because there son insisted they get a more economical car – (and were embarrassed about the 1985 Cortina that mum and dad  were running around in), don’t beat yourself up, you most likely live a busy life and have responsibilities that take up a lot of your attention, misfuelling is not the beginning of dementia, nor is it indicative of a low IQ, anyone who gives you a hard time or carries the joke on too long, is probably the sort of person who has a go at everyone about everything, so don’t take it personally, one day it will happen to them too. The “at risk groups” are mothers with young children, (try filling up with  toddlers),  anyone in a rush, fleet drivers who run a petrol home car and diesel work car, and of course Muppets  joke;-)


Q; Does the petrol seperate and float on top of diesel or does the diesel float on top of petrol

Answer; neither, they blend instantly in the tank and it becomes a fairly even mixture, although they are different compounds, (technically speaking the carbon chain on diesel is longer) , they both come from crude oil,  petrol and diesel spend millions of years in the ground as one and the same as part of crude, only refining seperates them, and once recombined they will mix together and stay together  untill refined.


Q; I have heard of petrol being used as an additive in diesel in colder climates, why?

Answer, yes, it can be used as an ad-hoc winter fuel additive, in remote freezing areas that do not have a well established supply chain of fuel, (think Arctic weather stations), in the UK however we have a very good supply chain of fuel and winter additive is added by the refiners as early as September, the engines that can tolerate a bit of petrol are lower technology diesels, that do not have the high pressure pumps that are found in the cars of today, I would not recommend using Petrol as an additive to diesel, I heard from a  skip hire company in edinburgh that used to add petrol into diesel – but they stopped doing it in the 90’s


Q; My engine management light has come on – what does that mean?

Answer: Engine management lights come on for a number of different reasons, on Volkswagons for example when they have been driven on the wrong fuel and drained, they often take a while to restart sometime 3 bursts of 30 seconds cranking, it is not un-common for the low oil light to come on when it first fires up, it goes off after a minute or 2,  engine management computers are not very informative, they either say – “no problem” or “problem”, petrol in a diesel car will confuse sophisticated engine management computers, they are designed to regulate air and fuel flow, air pressure, exhaust pressure, exhausttemperature, ignition timing, all to give optimum performance, economy and emissions, when you put petrol in the tank it throws all the calculations off, some very intelligent engine management units cars will even try to “adjust” to the contaminated fuel, and when they fail as they always do, they will sometimes read a fault, the vast majority of fault codes generated by a wrong fuel scenario are temporary, which means once a fuel drain has been performed – the engine will detect that the conditions that caused the problem are no longer present – thus assumes the problem is solved and the EM light will go out, It is very rare that a light stays on after a fuel drain and restart, this is one of the reasons why I would always suggest a professional drain on a new car, a professional drain will remove as much fuel as is possible, which mitigates possible damage


Q; I put the wrong fuel in, do I need a new fuel filter?

Answer: No you not need a new filter. This idea came about from the “logical” assumption that the filter would be contaminated with condensed amounts of wrong fuel and thus continue to weep wrong fuel into the system, a filter does not hold much fuel – and petrol and diesel certainly do not “condense” 300 to 400 ml of fluid is what a filter holds, the filter is simply a housing, with a cardboard, paper type filament to catch solid debris, a diesel filter has 2 purposes, to prevent water from getting into the engine via a water trap – which needs emptied on servicing or by dashboard warning light sensor,  and to stop solid debris from the tank from getting into the engine, diesel and petrol are neither, and petrol does not “sit” in a fuel filter, likewise when diesel is put in a petrol car it does not sit in the system  when a fuel drain is performed of a car that has been driven to failure on wrong fuel a flush is done of the filter, this involves pumping the correct fuel through the filter, which purges the filter completely, after a proper fuel drain a filter will be clear of the wrong fuel, I think that this is sometimes used as an excuse by some garages to inflate the price of a fuel drain, the truth is that most fuel filters cost a whopping 4 pounds, and take a lenghty 6 to 8 minutes to change, I have seen garages charge over 150 pounds for a filter change, and If I was morally bankrupt I would be getting in on it to, but the truth is that there no reason to change a filter unless it is due per the service book, that said some people still want filters changed during a fuel drain for peace of mind, which I have done occasionally if the filter is supplied, for the princely sum of a cup of tea and a heap of biscuits, (chocolate).

Further reading;

a very good article on this subject was written by auto express, here is the link here

http://www.autoexpress.co.uk/news/autoexpressnews/221523/how_misfuelling_could_mean_a_5k_bill.html

This was re-hashed by the daily mail here

http://www.dailymail.co.uk/news/article-565840/Drivers-filling-wrong-fuel-fleeced-bills-high-5-000.html

Q.  who owns Fuelfixer

A.  Wrong Fuel company, Fuelfixer Ltd, is owned by the  managers of fuelfixer, Stuart Guy and “Dan the man Garside” (smoking hot wife) are the majority owners, Stuart and Dan bought the business from the man who started it – Murdo Guy, – (Stuarts older and better looking brother – and according to many more intelligent as well) Murdo Guy started the business in 2010. Murdo has gone on to smaller and better things, for instance if you need tyres in crawley he is your man.


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340 thoughts on “Wrong Fuel?Petrol in Diesel FAQ’s

  • Emma

    Hi I put unleaded into my 2009 Honda CRV. I drove approx 2 miles before I notice a change in my engines performance so pull in and called recovery. I had the car drained and was told to put diesel in and drove home. Car ran fine for just over a week now it struggles to start when engine is warm. Took to main dealer who said I needed a new fuel pump and filter, also said that when they took off the fuel pipe it smelt really strong of petrol? Could it need a new fuel pump? Why would there still be unleaded in the pipe?

    • TheFuelMan Post author

      Hi Emma,
      Sorry to hear about your situation. Unfortunately there is no simple answer to your question. However I’ll try to explain:
      Yes – running a car on the wrong fuel can damage fuel pumps – although it is not very common at all.
      Yes – it is highly advisable to get the fuel filter changed after a misfuel – especially if the wrong fuel was sitting in the car for any extended period of time.
      From what you described it sounds like whoever drained the vehicle didn’t get all the contaminated fuel out of it. What I would suggest is to get the tank and fuel system thoroughly drained and flushed out with clean fuel. Then check if you need to replace the pump. It could just be that there is enough contaminated fuel in the system to be causing the problems, and a proper drain would sort it out.
      Hope this helps.
      The Fuel Man

      • Emma

        Hi
        What do you charge for a drain and flush?
        I have already had the fuel filter replaced hoping that would resolve the issue but it hasn’t
        I have been accused of misfueling my vehicle a second time as they cannot explain how my car would drive and how there is such a strong smell of unleaded,
        Is there any way I can prove that the drain and flush was not done correctly

        • TheFuelMan Post author

          Hi Emma,
          Unfortunately there is no way to prove anything – other than trying to provide fuel reciepts.
          If you would like a quote for us to come out and correctly drain the vehicle, give us a call. Or reply to this with your number and I’ll call you.
          The Fuel Man

  • John

    Hi,

    I am driving a 2015 1.6 CDTI Opel Astra. I just made the mistake of putting about 1 litre of unleaded petrol into my car, I then brimmed it with diesel. The tank capacity is 56 litres so I put in just under 2% petrol. I rang a mechanic I know and he said it would be fine and to drive on. What is your opinion? Could this small amount of petrol be enough to damage my fuel lines or pump? Would dipetane be good enough an additive to add to help lubricate the fuel system? Thank you for your time.

    Regards,
    John.

    • TheFuelMan Post author

      Hi John,
      It is very uncommon to hear of that level of contaminated fuel causing any significant problems with a vehicle. However, bear in mind that each case is individual and a lot will depend on the quality of the fuel and your car parts.
      If it were my car I probably would have done the same in brimming it. However I would be using an additive that specifically says that it helps with fuel system lubrication. I’ve looked over some Dipetane documentation and cannot find any reference to it doing this.
      Hope this helps,
      The Fuel Man

      • John

        Thank you for the quick reply and sharing you knowledge, you are a gentleman. Its takes a load off my mind. i will get a quality additive with a lubricant in it and put it in.
        With regards to dipetane (I have half a bottle at home from my last petrol car, that’s why I mentioned it) I got this from their site from their FAQ’s under injectors : “The easiest way is to use Dipetane which is designed to keep the injectors ultra clean and to provide the added crucial benefit of extra lubrication. The additional lubrication which can only be provided by Dipetane will counter the decreased lubrication due to the 80% cut in sulphur in diesel fuel. Sulphur in diesel had been providing vital lubrication to protect the injectors from wear and tear, Dipetane now compensates for this loss.”

        Thanks again,
        John.

        • TheFuelMan Post author

          I hope it works out for you.
          As regards Dipetane, I’ve never used it and so cannot really comment. All I can say is that their general reviews and forum comments are not-too-positive. This, together with the fact that their website hasn’t been updated for over 2 years, tends to make me a little suspicious. Having said that, it might be the wonder product it claims to be. I’ll have to try it out one day to find out.
          In your case – I would suggest not experimenting right now – just find a recognised diesel-specific lubrication additive to be on the safe side. Experiment when you know for sure there’s nothing wrong with the car.
          Best of luck,
          The Fuel Man

  • karen

    I put 20 quid of petrol in my diesel corsa. I drove 10 miles home when I went to start car next day I realised what I had done straight away and turned car off. my mechanic friends drained the petrol out and we refilled tank with diesel. all seemed ok for 2 days then car started to lose power when I slowed down at a junction or a round out when I try to get my speed back up it loses power I pull over switch car off then on again an all is fine has done this 4-5 times in 2 days any advise

    • TheFuelMan Post author

      Hi Karen,
      Sorry for taking so long to get back to you. The first thing to find out is if your friend managed to get all the contaminated fuel out of the vehicle (including clearing out the lines and filter). It is most likely the case that there is still a fair amount of it left causing the problem with a lack of power.
      Let me know.
      The Fuel Man

  • John Mansfield

    Thankyou very much FuelMan for your quick reply, I feel reassured by yourself that there shouldn’t be any concern, I am going to put an additive in as you suggested, Thankyou once again, John.

  • JP

    Superb info and am all the better for reading it. Diesel Peugeot started playing up recently:engine cuts out sometimes when slowing down or when idling(though next journey may be fine and so on – i.e an erratic fault). Always super-careful when fuelling but wanted to eliminate this as poss cause. Had originally topped up with 1/2 tank fuel,drove approx 90 miles before it then started playing up following day. Cousin takes the car for 3 days – no probs. Car back+been playing up since! Has probably been driven for approx 100 miles since. Neither garage nor auto electric folk who have taken a look have mentioned anything re wrong fuel as a poss theory and I’m 99% certain it is not that. Your website I thinks backs this up. Thanks

  • John Mansfield

    Hi FuelMan, Please could you help, i drive a Range Rover Evoque 2.2 diesel 2013,.Today i accidently put 48 pence worth or 0.45% of a litre of unleaded petrol instead of diesel, i realised and stopped straight away i then continued to fill the tank which took 45 litres of diesel to fill.The tank itself holds 60 litres of diesel, i am concerned i may have damaged the engine, should i consider having the tank drained, or is percentage of petrol against diesel to low to be of concern, what do you recommend. Thanks John

    • TheFuelMan Post author

      Hi John,
      I’ve never heard of that amount of wrong fuel causing any issues at all (I hope your case isn’t the first). If it were my car it’s not something I would be overly concerned about.
      Obviously for legal reasons I have to remind you that every case is individual and that any amount of contaminated fuel can cause issues. But in all honesty I wouldn’t just be surprised if it damaged anything – I would be shocked.
      If you want to mitigate any possible chances you should get a lubricating additive into the fuel.
      Hope this helps.
      The Fuel Man

      • Mike Cryne

        Hi Fuelman,
        I have stumbled on you site by accident while trying to resolve my gas (petrol) in diesel dilemma in the USA. There are not any services like yours in the US that I can find, only dealers and local mechanics / garages, with VW TDI experts in sparse supply. I am greatly relieved to hear of the results normally achieved by a complete drain and filter change and in some cases (very small contaminations) simply diluting with diesel and adding a diesel conditioner w/lubricant. That said I fear that I am the unlucky one who drove our 2006 golf TDI (BEW PD engine in states) about 25 miles before it died on the highway. I did not figure out it was petrol contamination for about two weeks, I looked at the last receipt for about 6 US gallons and it said diesel ( apparently the stations diesel tank was contaminated by a miss filling). I have now opened the tank and cleaned it as well as drained the lift pump, fuel lines and changed the filter. I primed the filter with diesel purge, put 5 gals fresh diesel in the tank and added 5 oz of Kleenex diesel additive with lubricant, cycled the lift pump a dozen times and tried to start with no luck. The battery is fully charged and the engine cranking over nicely it has tried to catch a few times but seems to not have fuel. I fear I may have gotten a mix of petrol to diesel that allowed the engine to run just long enough to ruin the injectors and more. The lift pump seems to work fine but there might be air somewhere in the system yet. Here in the states very few people have specific expertise in the fuel mistake/recovery area due to the lack of available diesel personal vehicles and as a result you only hear horror stories about catastrophic failure and multi thousand dollar repair bills, almost no one including TDI forums will tell you that a complete tank drain, line flush and filter change with fresh fuel will solve many problems, in fact 90% or better of what you hear is catastrophe failure and $1000 – $3000 for 2006 and earlier TDI’s and $3,000 -$8,000 for 2009 and up (no ’07 or ’08 TDI’s in US). I would have gladly paid for a service to drain my vehicle and dispose of the 15 gallons of @20% petrol diesel that I have to deal with. I can’t help wondering if a “fuel repair” specialty company would do well in major metropolitan areas in the US, i.e. NYC, DC, LA, Philadelphia , Chacigo. Mike

        • TheFuelMan Post author

          Hi Mike,
          Sorry to hear about your situation. When you turn the ignition, is there fuel? Disconnect the fuel line and check if fuel spurts out when you crank it. If not it could be a problem with the lift pump. If you are getting fuel then it should eventually start on cranking (I find that spraying a tiny bit of break-cleaner into the air intake helps give it a little push).
          Let me know if that works out for you.
          As regards setting up shop in the US – I’ve actually looked into this before. Unfortunately last time I checked there aren’t enough diesel cars per square/km in the States to make it a profitable venture. We have tonnes of diesel cars here – and the country is tiny – and therefore easy to get around.
          The Fuel Man

  • James B

    Hi FuelMan,
    I own a 2001 Saab 9-3 TID.
    Today I went to fill up the car and realized that I was adding Super Unleaded not Diesel into the tank. I stopped but not before I added a half a tank to the car. I drove it (at most) 300 meters to a self service garage. I drained the fuel from the tank using a pump. Added 2 gallons of DIESEL fuel and now the vehicle will not start.

    Any suggestions on what I can do to make this thing start?

    Thanks in advance.

    • TheFuelMan Post author

      Hi James,
      It sounds likely that you still have unleaded in the fuel system. Draining the tank on a misfuelled vehicle that has been run is very often not enough to get it going again. It will also require draining and flushing out the system (lines, filters, etc.). This needs to be done carefully to ensure that there are no air-locks which would also prevent the vehicle from starting.
      I very highly doubt that driving the vehicle 300 metres would have damaged anything so I would suggest that the drain just needs to be completed.
      Hope this helps.
      The Fuel Man

  • Colin

    Hi FuelMan …Thanks for reply,

    So far so good ive basically mirrored what Bruce done and have kept it brimmed with high grade and added another double dose of diesel additive/lubricant and fingers crossed 200miles since misfuel. It starts fine and fires up in a second or two and a lil bit of white smoke ot first, sounds a little tappynoisy under acceleration but seems to be getting quieter after each top up.
    My one question if you could answer is, When I add diesel will the petrol rest on the top? Or would it mix with the diesel ? Only I dont think Bruce could confirm that in his post.
    Thanks Again.

    • TheFuelMan Post author

      Hi Colin,
      Good to hear your luck is holding.
      As to petrol resting on top of diesel – no. They mix like milk and water. If you were to leave it standing for a loooong time you would find a higher concentration of one at the top – but they would still be pretty well mixed. Bear in mind that they come out of the ground mixed, and it takes further refining to re-separate them. Also remember that hot fuel is constantly being pumped back into the fuel tank when the engine is running, causing any newly added fuel to be almost instantly mixed in as well.
      The Fuel Man

  • Colin

    Hi
    I have a 2005 1.8 tdci Transit connect,
    My low fuel light came on and i pulled into fill up but made the error and pit 10 ltrs worth in without realising, drove off and engine management light came on under acceleration in 5th gear it was then the penny dropped and i noticed my error… pulled into next station [10 miles down road} and brimmed to full on higher grade diesel and added diesel additive the management light did not re-apear and i completed my journey with no issue { so far} it also started this morning ok and seems to be running fine, do you think ive just been lucky or could i have problems ahead.
    I will continue to brim with higher grade diesel and add another dosage of additive when i get to 3rd of tank so just hoping, any advice or guidance on whether i should get system drained or would i have experienced the symptoms by now?
    Thanks for any help you can offer in Advance
    (Just a quick add, the journey from brimming with high grade was roughly 70 miles.)

    Colin.

    • TheFuelMan Post author

      Hi Colin,
      Sorry for the delay in getting back to you.
      Have a look at this comment from Bruce. He was in a similar situation and he describes what he did and the results of it.
      Best of luck,
      The Fuel Man

    • TheFuelMan Post author

      Hi Andy,
      This is a question we get asked quite a lot as it is very much a grey area for most people.
      Have a look at this comment from Jules, and the subsequent replies from me and from the motorist. It might help ease your mind.
      Best of luck,
      The Fuel Man

  • Bruce

    Last weekend put 3.4lt of unleaded into my 64l diesel tank – it had 20lt in, panicked and took a risk and brimmed it with 40lt – so about 5% contamination. Drove 1000 miles over next four days, kept topping up (5 times) so tank never below 2/3rds full with BP Ultimate rather than ordinary diesel. Kept engine revs to under 2,000 by keeping within speed limits! By my calcs, assuming petrol mixed evenly with diesel contamination should now be around 0.8%. Have put in 101 litres since first brimming. Car drives absolutely fine, returning 45mpg over long journey. My calcs suggests another 100 litres (say 5 top ups of 20lt) will bring contamination down to 0.1%

    So have I been lucky or can I expect future problems – and in a years time when the car goes in for service (after a further 8000 miles) will VW dealer be able to detect what I’ve done – car is still under warranty. Is it still worth getting a full drain?

    • TheFuelMan Post author

      Hi Bruce,
      With only 3.4Ltres in a full 64Ltre tank (filled with BP Ultimate) I do not expect you will have any trouble. Your contamination level is sufficiently low – and you are using diesel with added lubrication (BP Ultimate) – that any negative effects of the petrol in the system should be almost entirely nullified.
      I doubt very much that a fuel drain will make any difference to the vehicle now. And after another 8,000 miles I very highly doubt anyone will know what’s happened (I don’t think anyone could even tell now bearing in mind that some of the fuel you can buy at some supermarket petrol stations is a bit dodgey and, under analysis, probably looks a like Ultimate diesel with a bit of unleaded mixed in).
      Best of luck,
      The Fuel Man

      • Bruce

        Thought I would leave an update here so readers have so real data on outcomes. Now driven 1,750 miles since the 3.4 litre misfuel – and have put in a total of 223 litres of diesel since – 155 litres were BP Ultimate or Shell V Power. Haven’t noticed anything at all out of the ordinary from the engine, noise wise or performance wise, and have got 39.9mpg overall since the misfuel and on some journey’s up to 49mpg. Prior to misfuel average was 37.3mpg. Have filled up 10 times never letting fuel get less than 2/3rd full apart from today when tank got down to a bit above half full – 30 litres needed. Have kept revs to under 2000 as much as possible but on occasion had to make the engine work hard up long 16% hills.
        Had a nervous moment when car went in this week to dealer for a warranty recall to have a ‘regulating flap’ fitted, but dealer didn’t make any comment about the car.
        Have tried to calculate how much petrol is left mixed in with the diesel. Making the assumption that every fill mixes entirely evenly with what was there already (not necessarily the case), I’ve calculated that with my fill pattern the tank has gone from a % petrol of 5.1% at misfuel (after brimming) in the diesel down to 0.12% now. It’ll get down to 0.01% after another 120 litres (2 more tankful’s, 6 fills).
        I’ll provide an update at the 2,500 miles since misfuel or earlier if there’s a problem. I’ll be continuing to fill up every 20 litres or so with Shell V-Power. Good job diesel has got cheaper!

        • TheFuelMan Post author

          Hi Bruce,
          Thank you very much for this information – very useful for our readers!
          Glad that it has all worked out for you.
          The Fuel Man

          • Bruce

            Thought I’d give a final update – have now gone 2800 miles with no problems at all. Have continued to refuel to brim every 25litres or so. My calcs show that petrol should now be just 0.01% of a tank full compared with 5.5% at start.
            Looking back on the experience I would now go for a tank drain – too much worry otherwise! At the time I was filling up and immediately going on a 1,000 mile weekend round trip and short of time. Delaying starting for 2 hours whilst tank was drained would have made for a much more relaxing time. However by doing the 1000 miles (almost all dual/motorway at 70mpg) in 3 days I got the petrol heavily diluted quickly and reassured myself quickly …. and avoided having to tell the wife! Still not sure if there might be long term damage which hasn’t shown up yet, but car is still under warranty ( a year to go). Will be keeping putting in V-power/Ultimate to minimize any long term effects.

  • Cheryl

    Thank you so much for your very informative reply.

    In addition to the advice I had received, on SaturdayI did also contact two garages that I have used in the past
    and BOTH of them told me that I shouldn’t have a problem at all; in fact, one of them told me he
    would not actually see it as necessary to drain the system at the % I had put in. BUT BUT BUT,
    I was still worried – still am. Knowing it is an older car – and thus less likely to have a problem – means,
    to me, that I should take the best care of it as I really do not want to have problems looming over
    the horizon. It would be nice to think I shall replace the car soon – but, to be honest – I don;t see it happening.
    So I do plan to arrange to have the system drained before I have much more driving to do. I have driven
    probably 40 miles max.over the weekend (since the problem Friday evening) – would this mean that
    there is no point in draining?
    Again, thank you for your help so far.

    • TheFuelMan Post author

      Hi Cheryl,
      First off I would say that I can’t find any fault with the advice you have been given on this matter. In the majority of cases I’ve seen like this there have been no long term effects of the misfuelling. However there is always a chance that something could go wrong, specifically on an older car that already has substantial wear and tear on the fuel system. If you are really worried about it – get it drained. This will give you the peace of mind you are looking for as it will ensure no further damage can be done to the vehicle. But I don’t know that I would bother too much with it if it were my vehicle. I would probably just go for getting a lubricating additive and have the fuel filter changed.
      Give us a call and we’ll be happy to further assist you.
      The Fuel Man

  • Cheryl

    Hi – fpr the first time in 8 years, I put the wrong fuel into my much loved but very old (R reg) Passat 1.9 TDi.
    I noticed at about five and a half litres and stopped, thinking I was going to pass out from the stress. The tank was just under
    half full prior to putting the petrol in and I was about to top up to full for a saving of 4p on a litre. Ha ha.
    I called Fuel Doctor who after checking car, amount I had put in etc., told me to fill the tank and all would be fine; under 10%
    of the tank capacity will be OK.
    This was also backed up by the attendants in the petrol station.
    Drove home perfectly fine, no issue whatsoever. This car has been very good and always starts first time and runs well,
    although is obviously old and does sound like a taxi.
    Now have read this entire comment thread and am worried that other. more insidious problems will arise (plastic pipes “melting”,
    filters clogging and even injectors being ruined….. etc.) and I am now a wee bit worried – – to say the least ;o(
    I don’t know if you will see this or have chance to respond – and I am not even sure if your company covers my area as
    I don’t see it on your list (South Yorkshire) – but I would be very very grateful for your advice based on my situation.
    :o/..

    • TheFuelMan Post author

      Hi Cheryl,
      I’m sorry to hear about your situation. Rest assured that we do cover your area – in fact we are fully nationwide.
      About your car: I would tend to side with the advice that you have already been given. If I’m not mistaken the 1997 Passat has a 70litre tank and therefore your contamination level is about 7.5% (assuming it was topped up afterwards).
      Realise that the “under 10%” advice that you were given is simply a guideline based on experience and is not a hard and fast rule. I’ve seen people get away with higher contamination levels, and also seen problems develop with lower levels.
      It is my opinion that putting this much petrol through a common-rail diesel engine is equivalent to running a very crude and abrasive cleaner through the system. Most engines will have no particular problem with it – but some will. Unfortunately there is no way to tell which way the pendulum will swing without trying it.
      If the future health of the vehicle and peace of mind are likely to be very important to you, you might want to look at getting it fully drained out and cleaned.
      If you are willing to take the risks (and I honestly don’t believe that they are huge) then I would keep topping it up. I would also find a fuel system additive and get that into the tank (look for any diesel additive that says it helps to re-lubricate the system – this is important). Additionally you should get the fuel filters changed at your soonest convenience due to the fact that the petrol will almost certainly loosen fuel line gunk and deposits which will make their way into the filter and could help to clog it up.
      I hope this has been helpful. If you have any further questions don’t hesitate to contact us.
      The Fuel Man

  • Jeff Evans

    Very good information, thanks for telling me in time to save me from selling my body parts to pay for a main dealer fix; ps the wife says my body parts are too knackered to sell anyway, regards jeff.

  • ijroute

    Absolutely brilliant write up from someone who definitely knows what there talking about, reading this as put my mind a little easier as I have had to be towed back today after picking up a new (to me) car and was totally unaware that I had put petrol in instead of diesel thought the blue smoke and stalling was due to the car wanting a good “blow out” and that’s what I intended doing today until I got a few miles down the motorway and it just cut out without warning!

  • gerard

    Hi,

    Fuelled seat 1.2 ltr diesel car with £20 worth of petrol and then drove it for 20 miles before it broke down. At this point a large amount of white smoke was coming from car.

    It has been into seat garage and they have drained fuel and cleaned tanks however not fixed as yet. They have then completed a further clean of filters and still no fix.

    Today they have informed me when engine starts that a large amount of water and diesel is coming out from exhaust and indicating that a new engine maybe required.

    Have you heard of this before?

    Thanks

    • TheFuelMan Post author

      Hello Gerard,
      I’ll be honest – the water is a surprise to me as it’s not something that is normally associated with misfueling. A small amount of water vapour (and steam when the engine is still cold) is completely normal. However a “large amount” is not. This could indicate a clogged muffler or, more seriously, a blown head gasket. As regards the diesel coming out of the exhaust after a misfuel, this could most likely be caused by a faulty injector.
      If I were you I would get the muffler checked and the injectors tested. This should tell you what you need to know and the extent of the damage.
      The Fuel Man

  • Michelle

    Hi. I put 3litres of unleaded in my Nissan Diesel Juke today realised – and filled it up with Diesel . It’s been to Nissan for a service today that was already booked. Now I’ve collected it the mpg details keep changing every few seconds on the dash board! Flashes 99mpg then 28mpg etc. Is that something the garage has done wrong or because I’ve put unleaded in? Thank you.

    • TheFuelMan Post author

      Hi Michelle,
      When does this mpg change happen – while driving? It could be something as simple as the display was changed from showing Average Fuel Consumption to showing Current Fuel Consumption. If this is the case then resetting it to show average mpg will solve the problem. Take a look at this:
      Nissan Juke Multi-Function Display
      If this is not the case let me know and I’ll look into it further.
      The Fuel Man

  • Aaron

    Dear Sir,
    Greetings from Panama! I have a 1.9L TDI Diesel Skoda Octavia (Pumpe Düse unit injector engine, apparently). I stupidly put in a 90% tank of unleaded and drove 25km. It misfired a couple of times then but I wasnt sure because the road home is very bumpy. Then When I stopped and lowered the revs it knocked very hard. I turned it off and tried restarting which it would not do so towed it the rest of the way home. I obviously will drain the tank, but should I drain the rest of the system too? Do you think I have ruined the engine? What a fool I have been!
    Thank you for any advice!

    • TheFuelMan Post author

      Hi Aaron,
      Yes, get the system drained as well – it can hold quite a lot of contaminated fuel. Then fill it up again and re-prime the system. Should be fine from there. I’d also get an additive into the system to lubricate the pumps as it has been driven quite a while.
      The Fuel Man

  • vrs

    so it would be best to get it drained when i change fuel filter? even though she is running perfect? and there is now 68 euro worth of diesel gone into it? and only 20 petrol

  • vrs

    I put 14 litres of petrol (20 Euro) in my 2012 octavia vrs. I was told to top it up with diesel as the tank was empty to start with. so i filled it up to the brim. (50 Euro) i then drove for about 100kms and put another 10 Euro diesel in and drove again for another 100k and topped up with 10 Euro more diesel. my mechanic is changing fuel filter in the morning and said that the car will be ok as i diluted it so much. What do you think. should i still get it drained. it seems to be running ok and starting ok

    • TheFuelMan Post author

      Hi,
      On an older car I would say just keep topping it up and use a fuel additive to help relubricate the pumps. However, on a newer vehicle – especially one under warranty – I would err on the side of caution and get it drained. If an old car packs up it’s not as big a deal as a new one as regards cost to get it fixed or replaced.
      The Fuel Man

  • Mark

    Hi,
    Added 1.5l litre of petrol to Diesel Kia Sportage (2013). Fully topped up with diesel and drove 15 miles. Should I get it drained, or should additive be safe enough?
    Thanks in advance
    Mark

    • TheFuelMan Post author

      Hi Mark,
      Most likely brimming it and using an additive will be ok. Obviously the only sure-fire solution is to have it removed but you will probably be ok like this.
      The Fuel Man

      • Mark

        Thanks for the prompt reply,
        Sorry to be pain, but can you advise what brimming it means (Just keep topping up with Diesel?). Is there a particular kind of additive I should use
        Mark

  • james

    Hi guys, i recently bought a used Citroen DS3, i was driving it for about 40 miles before it died, the slaesman who took me to the fuel station can confirm it was diesel he put in it( its a diesel car) but after the dealership had the fuel analysed and confirmed it had been contaminated, the salesman put in £20 of diesel in the car and i hadnt put anything else in it. upto now the report suggests that fuel pump is broke 2 of the jets and 2 of the cyclinders have loat compression so far, and the dealership are refusing tp repaire it even though i only had the car about 3 hours before it broke down.

    any advise would be great

    • TheFuelMan Post author

      Hi James,
      Wow. That’s a terrible situation to be in. Do you have access to the fuel receipt from the £20 that was put in? If so, what does it say?
      The Fuel Man

        • TheFuelMan Post author

          Hi,
          Unfortunately, yes. Although, to be honest, dealerships are notorious for overcharging for this services and often replacing parts that don’t need to be replaced. For instance, it is quite common for a dealership to want to replace everything that the contaminated fuel has touched – regardless of whether it is damaged or not. If I were you I would get an independant company out to do a full drain and flush on the vehicle. This would cost you less than £200. Once this is done you will know for sure if any further work is needed on the vehicle.
          The only real unfortunate point here is that you don’t know the vehicle’s history. If it has been misfuelled before it could be that all those parts you mentioned are indeed damaged needing replacing.
          The Fuel Man

  • Wazza

    Hi from New Zealand & Love your site.
    My wife owns a 2011 Toyota Prado 3litre common rail diesel (about 60,000kms on the clock)

    Today she put about 30 litres of 95 octane (unleaded) petrol in the Prado, (actually it was the service station attendant that did it) and then she drove it home unknowingly for about 7-10 kms (about 5-6 miles).

    When she got home, she said she noticed the motor seemed like ‘noisy tappets’ and had a couple of minor surges before she arrived home. It occurred to her that perhaps the car was filled with petrol and not diesel (The service station docket confirmed it)

    She wants to know what sort of ‘short term; and ‘long term’ damage might have been done and whether or not this should be an expensive fix?

    The car only had about 30-40 miles (50-60kms) of diesel left in thank when the petrol was added

    Really looking forward to your advice and feedback.

    Thanks heaps

    • TheFuelMan Post author

      Hi there,
      Presuming that the fuel is all drained and the fuel system completely flushed there shouldn’t be any real problem. However, long-term you have probably reduced the life-span of the fuel system components. Short-term it should be fine.
      If the fuel is not removed you are risking damaging the pumps and injectors.
      Have a look at this post.
      Hope this helps.
      The Fuel Man

  • Graham t

    I just filled my 2010 Freelander with unleaded. Got about 200 yards before I realised something was wrong & about another 200 yards before I could stop. My local LR dealer picked me up & informed me that the repair bill would be £5000+! Needless to say I contacted my insurers & hopefully they’ll be covering me but when a couple of months ago I filled my Laguna with unleaded @ drove 6 miles before breaking down, the AA came out, drained & flushed & I was on my way again! I cannot fathom what the difference is!

    • TheFuelMan Post author

      Hi Graham,
      Unfortunately the only difference is that you took it to Land Rover. Many, many people have asked this same question and here is the answer:
      Land Rover have a “zero tollerance” policy. This means that they are either unable or unwilling to guarantee any of their parts if they have come into contact with contaminated fuel. This does not, by any measure, mean that the parts are damaged at all. It simply means that Land Rover won’t guarantee them under warranty. Because of this they will decide that they need to replace the entire fuel system so that the vehicle is covered. They will tell you this without even looking at the vehicle to assess the parts. It really is a “zero tollerance”.
      Not only does this approach stop any customer complaints from faulty parts, but it is also a nice little money spinner.
      In my opinion there is absolutely no need to have any of this work carried out. Land Rover parts are not made so feebly that a brief washing with petrol will completely destroy them. Or maybe they really are that bad, as Land Rover themselves have little confidence in them!!
      Obviously there is a very, very remote chance that something has become damaged – but this is very unlikely.
      My suggestion to you is to get the vehicle out of the dealership and have someone come out to drain and flush it. I believe (I could be wrong so don’t quote me on this) that a certain recovery operator has a contract with Land Rover to recover all cases of 2010 onwards Land Rover misfuelling back to Land Rover to deal with. While unnamed recovery operator is more than qualified to perform fuel drains on these vehicles they are not allowed to by contract. This helps the dealership (with unnecessary repair bills) and the recovery operator (with a prime Land Rover Assist recovery package). Unfortunatley this means that you are unlikely to get much help from either.

      If I were you I would get the vehicle back home and tell the dealership that you are getting a second opinion. The EU Block Exemption ruling states that you cannot be forced to have the dealership only look after your car for purposes of warranty.
      I would then get a reputable specialist fuel drain company out to attend the vehicle – drain the tanks, flush the entire engine through and get it up and running again. And that would be the end of it. I very much doubt that anything at all needs to be replaced.
      We do hundreds of fuel drains every week and the percentages are less than 0.1% where a vehicle is damaged needing actual repairs or replacement parts.
      Sorry for my rant here, but these types of stories really make me mad. In addition to all this we recently carried out a little project to recontact our past customers to find out – one year or longer after we carried out a fuel drain – how their vehicle was doing. One for one they all stated that there hadn’t been a single problem with the vehicle – no need to replace anything, and no need for further repairs.
      Have a look through our many comments from Land Rover and Range Rover owners (also see http://www.fuelfixer.co.uk/misfueled-range-rover-prices/)
      Hope this sheds some light on the situation.
      The Fuel Man

  • Elizabeth

    Hi

    I have put £60 of unleaded petrol into my empty diesel car. I didn’t realise this until the car started juddering about 3 miles later, where I pulled over and stopped immediately. I checked my receipt and it confirmed I had put in unleaded rather than diesel. I immediately called the RAC who came within the hour and flushed it through. My husband has gone mad and told me I have ruined the car and it’s going to cost £5k to repair, it’s a nissan qashqai. However it seems to be driving ok today. Should I take it to the garage and have it repaired? Should I change the fuel filter? Should I use a lubricant like your posts suggest? Really unsure about what to do. Your forum is very helpful and I am hoping you can help me!

    Thanks so much

    • TheFuelMan Post author

      Hi Elizabeth,
      We often get called out to deal with vehicles drained by other companies – but we have never needed to attend one dealt with by the RAC. To my knowledge their technicians are very good at their job and if they did a full drain and flush your vehicle should be completely fine.
      I can’t imagine that you have done any serious damage to the vehicle at all after only driving it for 3 miles on contaminated fuel. I would also suggest that your filter, if flushed through correctly, does not need a change. Obviously, just to be completely safe, you could have this done.
      As you can see on our Feedback Page we have many reports from customers who have been in a similar situation to you and, after a drain was done, everything was ok. As a further bit of information, we recently went through our job logs and recontacted about 20 customers who had their vehicles drained by us over a year ago. One for one they all told us the same thing: that their vehicles were completely fine after the drain and they had noticed no ill effects at all up to a year later.
      So I would not worry about it. To be sure, yes – get the filter changed. You could even go as far as a full service if you feel the need.
      Hope this helps.
      The Fuel Man

      • Elizabeth

        Thank you so much for your encouraging feedback, you have been very helpful. Had I known about you, I would of contacted you before the RAC!

  • Simon

    Hi,
    I accidentally put a full tank of unleaded into my diesel Qashqai. I realised straight away and didn’t start the car. Called a fuel drain company who arrived within an hour and pumped the tank. He stopped and checked the fuel level a couple of times and told me it was done and I should fill up with diesel. I did this and he then flushed it through before I started. So far, so good. About 40 miles later just before home the car started juddering. Should I be worried?the other thing I noticed (not until I was back on the motorway though) was that after he told me the fuel had all been drained and I had put in 30 pounds-worth of diesel, the fuel gauge was showing over half a tank even though it would take 80 pounds to fill it from empty. This makes me nervous that it hadn’t all been drained, although it took a while for any fuel to come through when he manually pumped it with a bulb before I started the car.
    What do you reckon? Thanks

    • TheFuelMan Post author

      Hi Simon,
      Judging by what you have described, I would assume that possibly not all of the contaminated fuel was removed.
      Do you know if your vehicle has a saddle-tank or not? Some Qashqais do, but some don’t. Unfortunately, a common error made by inexperienced fuel drainer technicians is to fail to look for this and therefore fail to remove all the fuel from the second side of the tank.
      Of course, this is only one possibility, but it is something you should check first off. There could be other reasons for there still being contaminated fuel in the system. Or it could be a completely unrelated problem.
      Hope this is of some help.
      The Fuel Man

  • jules wright

    help, I put approx 500 mls of super unleaded in a nearly empty 12 plate quashqai and panicked and filled up with 55 litres of diesel. The forecourt suggested it would be OK, so drove 150 miles round journey. Just got home and then felt sick that i have not drained and have now ruined engine. How long will it last before it gives up the ghost? or if i add fuel additive, plus keep topping up with shells advanced diesel might i just get away with it, or has the 150 miles has already done the damage. I have turned of the auto stop/start as its a 1.5 with ecotechnology…does that mean its more at risk??????

    • TheFuelMan Post author

      Hi Jules,
      I doubt that 1/2 Litre of petrol would cause serious damage to your vehicle, especially because you brimmed the tank afterwards. To be on the safe side I would get an additive in there but I don’t think it would make a huge difference. Obviously there is no guarantee but I think you’ll be fine. I’ve not come across this amount of contaminated fuel causing serious issues before.
      The Fuel Man

      • jules wright

        just a quick update…. put in a fuel additive, have only topped up with either shells nitro diesel or BP advanced diesel, now done 2200 miles, without any problems…. hoping that it hasn’t done any lasting damage, but tbh, wont own it for more than a year onwards, so as long as it keeps going i will keep my fingers crossed. Thanks for putting my mind at ease though!

    • james white

      Hi
      i put 24 pence of petrol in my vw passat tdi. it was empty to start with so i filled up with £30 of diesel. its a 53 plate with 200504 miles. should i drain and flush or would putting a addictive in be ok?
      thanks jay

      • TheFuelMan Post author

        Hi James,
        I sincerely doubt that such a small amount of petrol will have any detrimental effect on your vehicle. I would fill it to the brim and possibly put in an additive. In 99% of cases this should be fine.
        The Fuel Man

  • Bon

    Hi put 3.3 litres of petrol in a passat diesel car, realised mistake so topped up tank (which was 3/4s full with diesel already). I drove 1 mile home with no issues but decided to get the aa to flush anyway. No issues since (I’ve driven 20 miles or so). Should that be the end of any issues? Anything I should look out for?

    • TheFuelMan Post author

      Hi there,
      With this small amount of petrol in the car , and then having it drained and flushed, I would be extremely surprised if you had any problems with the vehicle in the future. If you want to be very sure I would suggest that you get an additive into the fuel tank to help lubricate the fuel system.
      Hope this help.
      The Fuel Man

      • Bon

        Thanks a lot for that, It’s very worrying when you read all the horror stories etc. what additive am I looking for and how long should I use it for?

        • TheFuelMan Post author

          Hi,
          Anything that says that it help with re-lubrication of the fuel system. Have a look when next in your local petrol station. Most of them say that they are used for cleaning out the system – look for one that says it also lubricates. Put this in the tank when you fill up. Just the once should be fine.
          We use an additive called “Injection Correction”.

  • Neil

    Hi,

    I’ve put 9 pounds (10l), of unleaded into a Diesel engine, 2012 VW Touran TDi . The tank was low in diesel with light on, I panicked and put £54.90 of diesel to fill the tank near full. It could be topped up again.
    It’s roughly 11% unleaded to diesel. I’ve driven the car for 5 miles with no issues.
    I think I should drain.
    Any help would be really really appreciated.

    • TheFuelMan Post author

      Hi Neil,
      I’m very sorry for the delay in getting back to you on this.
      We generally recommend that anything over 5-10% contamination gets drained out. Having said that I know of people managing to get away with topping up after having a higher concentration of petrol. But I’ve also heard of people having problems with less. Unfortunately there is no real hard and fast rule on this and it’s a bit of a gamble. As you are talking about a fairly new car I would expect that it is quite valuable. If it were me in this situation I would get it drained. However, if the vehicle were a 10-year old clanger I would risk it.
      Have a look at the other comments below on this page and see what others have done in a similar situation.
      The Fuel Man

  • Michael

    Hi,

    I’ve put 0.7L, 90 pence, of unleaded into a Diesel engine, 08 corsa. There was roughly a 1/4 of diesel already in there, I panicked and put £45.90 of diesel to fill the tank fully.
    It’s roughly 1.6% unleaded to diesel. I stupidly didn’t realise this could damage the engine.

    I’ve driven the car for 30 miles with no issues.
    Do you think it’ll be ok as it was such a small amount?

    Any help would be really really appreciated.

    • TheFuelMan Post author

      Hi Michael,
      I don’t think this would be a big problem. To be perfectly safe I would get an additive into the fuel as well. You can pick one up at any petrol station for a few quid. This will help maintain lubrication – although, to be honest, 0.7l isn’t really much to worry about.
      The Fuel Man

  • Jonno

    Hi,
    completely filled my 07 plate freelander with petrol, the tank only had 10 miles range showing at the time. I drove for exactly 0.5 mile and then stopped immediately on the first misfire. The RAC arranged to tow me home and came next day (yesterday) to drain the petrol and add diesel.
    The RAC could not restart the car after draining it and adding diesel. I read the earlier thread which mentions that freelanders have dual tanks and checked with RAC that they did drain both tanks.
    The RAC have suggested I arrange for them to tow it to a local garage.
    Do you have any idea what the problem might be?
    Jonno

    • TheFuelMan Post author

      Hi Jonno,
      The RAC are usually very good at draining vehicles and I presume that they would have done a good job. However the thing to check is exactly what they did. They would have needed to empty both tanks and flush the lines, filter, pumps and injectors with clean fuel. If they did not do the latter then you would still have contaminated fuel in the system, which could be the cause of the problem. They might also have needed to reset any fault codes associated with the misfueling.
      However, if they have done all this you could be looking at a fault with one of your fuel system components. Obviously there is a risk of damaging something when driving a vehicle on contaminated fuel. If this is the case you will need to have those damaged components repaired/replaced.
      I hope this helps.
      The Fuel Man

  • Micky

    Thanks very much for your prompt reply. Just for your own and other reader’s information the Benz is a 200D Fintail. They undid the fuel tank drain plug and emptied all the fuel out. Probably about 60L in open containers. At this point a mobile food seller came to try and sell food, it is a kind of BBQ on a scooter and sidecar. I had to chase the guy away, sparks flying every where. Not good :-) Sometimes I wish I was in the UK….
    I have been thinking about the engine running a little lumpy after the fuel was drained and think this might be due to air in the system. When they had hand pumped the fuel through and bled the system it ran perfectly.
    Thanks again for your advise. I will be sure to check the filters.
    Cheers
    Michael

  • Micky

    Please can you help me out? What do you think of this? I am in Thailand and they don’t know about flushing through etc:

    The pump attendant put petrol in my 45 year old Diesel Mercedes Benz today. A full tank of petrol in an emptyish tank. Within 100m I knew what she had done. I drove another 300m and pulled into a back street garage. They dropped the fuel out and re-filled with diesel. We pumped it through and it started, a bit lumpy at 1st but after 5mins was OK.

    Do you think I caught it in time before it wrecked the rubbers and pipes etc?

    Pre this the engine was smoking a little bit when accelerating (black smoke). It has all but stopped now!

    Maybe the injectors were coked up and they have been burnt off. What do you think?

    I ran it for 30mins afterwards to get everything through, I hope. It’s probably had a couple of litres of petrol mix through I bet….

    Do you think it will be OK? Is there anything further I could? The car is running as sweet as a nut again now, if not a little better as it is not smoking now.

    Thanks

    Michael

    • TheFuelMan Post author

      Hi Michael,
      Nice to hear from Thailand!
      I wasn’t quite sure what you meant by “they dropped the fuel out”. Does this mean that they opened the drain-plug and let it drain empty? If so then most of the contaminated fuel would have been removed. Unfortunately this does not clear, as you rightly pointed out, the fuel in the lines, pump and filter. Without knowing what the model is I can’t say how much fuel that would have left in the engine, but I would hazard a guess at 5 to 10 litres. As long as you brimmed the tank the only other thing I would suggest is possibly using some sort of additive to help re-lubricate the system.
      To be honest, you are fortunate that you probably have an old-school diesel engine there. These are very sturdy and could probably take quite a bit of a beating before it fails. Having a small amount of petrol pass through the system has most likely helped to clean your pump, lines and injectors of any residue build-up. Unfortunately this means that you should keep an eye on your fuel filter to ensure that it doesn’t get saturated with gunk that has been flushed loose. If it starts to get really dirty change it asap.
      Hope this helps.
      The Fuel Man

  • Paul

    Hi Mr Fuelman,

    I managed to put unleaded petrol in my 2002 PD TDi Golf this morning. The tank was pretty much empty and by the time I realised I had mistaken the BP Ultimate (petrol) pump for the BP Ultimate (diesel) pump I had already put in 13.5 litres of petrol. (Same logo on pump handle. Plus I wasn’t concentrating of course!)

    The AA wanted £200 to sort the problem and I kind of baulked at that. In retrospect that would have been a good bet, but not realising all the issues involved at the time, I got them to tow me the five miles back home instead, it being a Sunday and the local garages being closed.

    I reckoned I’d be able to drain the tank myself OK as I was right on empty when I put the 13 litres in, and as I hadn’t started the engine I reckoned that would be all that’s required. However, when I got home I realised that every time I’d put the key in the ignition (and turned it half-way) the lifter pump would have pumped a burst of fuel towards the engine. (It would have been so easy to have taken the fuse out if I’d had my head screwed on.)

    So anyway I removed the lifter pump and siphoned the tank dry, removed (and discarded) the filter and blew any fuel back into the tank through the hoses and siphoned that out too. I refitted the lifter pump and looped the two hoses together at the filter end, put 5 litres clean diesel in and used the lifter pump to flush through the two hoses. The feed hose to the engine from the filter I disconnected and dropped down so what was in the end of that hose ran into a cup. As far as I can tell, what was in that feed hose was diesel – or very dieselly anyway. Slippery and warm between the fingers as opposed to the ‘dry’ and ‘cold’ feel of the petrolly mix I siphoned out of the tank.

    Am I right in thinking that no petrol will have been drawn into the the feed pipe from the filter to the engine if I didn’t turn the engine over? By turning on the ignition without turning over the engine would the fuel from the tank have simply gone up to the filter and back to the tank? Should I be OK now if I just put in the new filter, fill it, bleed it, put another ten litres or so in the tank and start the engine? By the way, the contents of the old filter seemed to be very ‘dieselly’ as well.

    The total amount of fuel that came out of the tank, etc. was about 16 litres – only 3 litres more than the 13 litres of petrol I put in – so I must have been right on the very empty end of empty. The car had been nagging me to refuel for nearly 100 miles by then I guess. I was surprised at how little fuel an ‘empty’ tank held but I looked with a mirror and could see no hidden ‘well’ in the fuel tank holding another 5 litres or anything like that.

    This has taken me the entire day as I’m not a mechanic and I was learning as I went, as well as proceding very gingerly as I was nervous. I really would have been much better off just getting the professionals to sort it but having got this far, it would be satisfying to continue and complete it myself. What do you think? Have I forgotten anything obvious?

    • TheFuelMan Post author

      Hi Paul,
      Looks like you’ve pretty much got everything covered. If I were you I would get the car back to a petrol station and fill it to the brim with clean diesel. If there are any remnants of petrol left in the system it will be diluted out. I would also either use an additive to help with lubrication or use Ultimate or V-Power diesel which already has additive in it.
      The Fuel Man

      • Paul

        Hey, thanks for the super-swift reply Fuelman. Your site is fantastic by the way. I think I had scared myself by reading all kinds of horror stories on various internet forums and various commercial sites. Your site was the first I found that was a) written by someone who knows what he’s talking about from vast experience, and b) was clearly designed first to inform and only second to make sales. I’m not planning on misfuelling ever again of course, but I’ve put your number and your web address in my mobile phone contacts list just in case I, or anyone I know, has a similar problem in the future. I’m happy to have saved myself some money this time, and learned something in the process, but I only contemplated doing it myself because I knew I had a very small amount of waste fuel to siphon out, store and dispose of. A full 70 litre tank of petrol would be another story entirely.

        • TheFuelMan Post author

          Hi Paul,
          Glad you found the information here useful and that you were able to sort the problem out. Best of luck.
          The Fuel Man

  • Frank

    Today I managed to mistakenly put 16 litres of unleaded petrol into a 2009 Honda CR-V i-CTDI SE, which was already 3/4 full with diesel. I then drove 90 miles up the motorway without noticing anything wrong. There was no obvious knocking or spluttering, but in hindsight it did feel sluggish under acceleration. After 90 miles averaging about 60 mph I stopped at a service station for a comfort break. I was then unable to restart the vehicle. I contacted the AA, and their question about fuel made me check the receipt from my earlier fuel purchase, which is when I realised the mistake.

    I paid for the AA to come and do a fuel drain which was completed within 2 hours of reporting, with the AA man putting £12 of fuel plus lubricant additive into the tank after the process was competed. The car started first time. I then put an additional £45 into the tank. I continued my journey, listening for any problems. I completed another 140 miles without problem, stopping one more time. The car started first time after a 30 minute break towards the end of the 140 miles second leg of my journey.

    Once at my destination, I also managed to restart the car first time, 2 hours after arrival when I went to check everything was still OK. But I am still feel I must have done some permanent damage given the distance I drove with the 1:3 unleaded to diesel mix. What do you think? Any advice will much appreciated. Thanking you in advance.

    • TheFuelMan Post author

      Hi Frank,
      As everything seems to be running fine I would suggest that you have not done any serious damage to the vehicle. However it is fortunate that you stopped when you did and continuing to drive with that ratio could have been a costly mistake.
      The only likely damage is that you have shortened the life-span of some of your fuel system components like the high-pressure pump. Obviously this is not something that you will notice now, but probably in the future when you find you need to replace components earlier than expected.
      Other than that you should be absolutely fine.
      Hope this helps.
      The Fuel Man

  • Steve granger

    I just put 6 pence worth of unleaded in a diesal car, I realised almost straight away and topped the car up with diesal, will it be ok?

  • Mike

    Hi Fuel Man
    I put 38.5 litres of petrol in my 2008 skoda octavia, drove off and the engine stalled at traffic lights about threequarters of a mile away. It did eventually start but was very awkward and would stall at low revs.I then realised what I had done and had the tank emptied and then filled to the top with fuel, about 45 litres. The engine really struggled to start, needing to be churned over for quite a while but went OK when running. I drove to my daughter’s about 3 miles away and stopped the engine, stayed for about ten minutes and tried to start, struggling again, I then drove about 45 miles home. I went to the car this morning expecting problems but it started immediately but when it is hot again it struggles, it seems the colder it is the easier it starts which does not make sense to me. Any ideas?

    • TheFuelMan Post author

      Hi Mike,
      Unfortunately you will need to get the tank drained. Having half a tank of petrol in a diesel car will do nothing but ruin it. The longer you drive with this the more likely you are to damage the sensitive high pressure pump and injectors.
      Give us a call and we can discuss it further.
      The Fuel Man

  • Lewis conways

    I put this to the vauxhall garage and all they did was reset it out of limp mode and test drove it for a while and it drove fine. No problems at all since either ! Should I look into getting fuel filters changed then ? I got the vehicle professionally drained by fuel doctor but I’m not sure of that included drains the filters etc. they also put a lubricant substance in the engine to help it:

    • TheFuelMan Post author

      Hi Lewis,
      I would suggest that you should be fine.
      Changing the fuel filter wouldn’t hurt as its life-span has almost certainly been shortened by having petrol run through it. However, I don’t think it would be a big problem if you left this until the next scheduled service if the contaminated fuel was not in there for any expended period of time. Check with your dealership what they would recommend for your vehicle.
      The Fuel Man

  • Chuck

    Mr. Fuelman I lost my job today because I was told to
    put gas in lawnmower and cut yard. I went to gas station and put gas in can came back nd put gas in mower that ironically I was told to keep it running while I go get gas but was never told diesel. Got on mower and rode 3 minutes top and mower began to lose power. I give off got tell employer mower is idling funny and he asks what kind of gas did I put in. I told him regular gas and he gave me my pay for the day and told me goodbye. Walked away and said “that’s a diesel mower, red container is for gas, blue container is for diesel or kerosine, goodbye” I asked if I could siphon the gas out but he ignored me and proceeded to walk away. apologized but was if.o

    • TheFuelMan Post author

      Hi Chuck,
      Wow. I’m sorry to hear about your situation. Unfortunately your post was cut off and I don’t know what you wanted to ask. Please could you post your question again?
      Thanks,
      The Fuel Man

      • Lewis

        Hello, I recently filled my new Diesel Vauxhall corsa 62 plate 18500 mile with 90 % petrol and 10 % Diesel after stupidly filling it up with petrol at the station. Upon 4 miles driving the car cut out and I had to be towed back home. Upon being back home I then got a fuel doctor out who drained away the petrol and put some diesel in. The car then went into limp mode which basically runs the car at a low percentage to save the engine when the engine light comes on and senses something bad, because the I took it to my manufacturer who ran a diagnostics test on it and reset the engine which is now running completely fine like before. What I want to know is have I damaged my car in the long term ?

        Thanks

        Lewis

        • TheFuelMan Post author

          Hi Lewis,
          If the fuel was drained completely, including purging all the lines, filter and pumps, there should not be any problem. It is very common for modern vehicles to go into limp mode when they have been misfueled. This would have happened while you were running the vehicle on the contaminated fuel. If this happened after the fuel drain was completed then it would indicate that there was still contamination in the system.
          It is so common for this to happen, in fact, that all our engineers are equipped with diagnostic tools to enable them to read and clear fault codes associated with misfueling.
          Hope this helps.
          The Fuel Man

  • andrew

    hi my 59 plate golf tdi was misfuelled around a month ago, the car cut out around 3 times within a mile so we got it picked up by recovery and was taken to the dealership, the mechanic told us that there was petrol in the mix and when he done a burn test it only burned for a couple of seconds, he flushed/cleaned the engine £280, now a few days ago ( a month after misfuelling) it cut out another 2 times within around 2 miles, we drove straight home and put it back in the dealership, they called us today and have said they have found a fault with the ECU and have sent it to the VW dealership to be checked, will the problem with the ECU have come from the misfuelling?

    • TheFuelMan Post author

      Hi Andrew,
      If you are being told that the ECU is damaged I have never heard of the ECU being in any way affected by a misfuel other than giving false readings. This will not damage the unit. It could simply be a coincidence.
      However, If you meant that the ECU is giving a fault code then this is entirely possible. If this is the case you should have then get it on a tester to read what the code is. Once you know what the fault code refers to you will be in a better position to see if it is a result of the misfuel.
      The Fuel Man

      • andrew

        thank you for the reply, they said that they found a “problem” with the ECU and they were sending it to the main VW dealership today, so i should find out better today, would i be better having VW do the work or take it to my local independant garage?

        • TheFuelMan Post author

          Unfortunately if there is a problem with the ECU there are only really 2 things you can do with it – either reprogram it or replace it. In either case you would probably want it to be done by VW themselves to ensure it is done correctly and it will be covered by a parts warranty.

          • andrew

            i thought i would let you know what has happened, the VW dealership in bogside south lanarkshire contacted us and have said there was contaminated fuel in the system after arnold clark in motherwell saying there was a problem with the ECU?? my partners brother works with taggarts and contacted a old workmate who now works with the main VW dealership in scotland, whose exact word were ” don’t let them touch a thing there is something funny going on” i have since found out that in 2009 VW sent out a notification for my year/model of car advising of possible fuel pump defects, could this be why i have been told of having contaminated fuel in my system? iam sorry if iam clogging up your thread, but iam at my wits end with this :(

          • TheFuelMan Post author

            Hi Andrew,
            I know someone who used to have a van that was intentionally run on contaminated fuel. The van broke down and he took it in to the dealership to get it fixed. The van was with the dealership for over 3 weeks. In that time they replaced the throttle body, the ECU, the cat and some other minor things – each time saying that it was now fixed. Unfortunately it wasn’t.
            It was only after telling the dealership that the van had been run on contaminated fuel that they cleaned out the fuel system and replaced the filters. This solved the problem he was having with it.
            Unfortunately contaminated fuel issues can appear to be something completely different if you don’t know what you are looking for and don’t check for it.
            I’m familliar with the fuel pump issues on the VW Golf, Jetta and some Audi models manufactured between 2009 and 2012. These pumps are especially susceptable to damage in even the slightest case of misfueling. It would seem that when VW made changes to their engines to comply with emmissions regulations in 2009 someone dropped the ball when redesigning their high-pressure pumps.
            If there is contaminated fuel in your vehicle it is very possible that this has affected the pump. Unfortunately this is not covered by the VW warranty.
            However, if you are sure that your car has never been misfueled you should request a full fuel analysis. If this shows that the diesel is “clean” then you might be able to get them to replace the pump for free (if still under warranty or within your insurance policy).
            Don’t worry about “clogging up” the thread. It is exactly these types of questions that we encourage so that others reading here can learn more. Please do let us know what you decide to do with your vehicle and the results of these actions.
            The Fuel Man

          • andrew

            hi again, we have had the car at the VW dealership in glasgow to have a master tech look at it, and they have now told us that we need 4 new injectors and said it would be highly unlikely to be caused by a misfuel and no mention of a problem with the ecu, we paid once for the engine to be flushed and then the problem came up again and VW in bogside south lanarkshire said it had been misfueled again, i went straight to the petrol station who have my receipt and have me on CCTV putting diesel in my car, when i went to pick my car up the story went from a misfuel to contaminated fuel to them then saying they did not know if it was contaminated or not?? to me this sounds as though volkswagen in bogside were just guessing at what the problem was and were trying there luck to get another £300 out of me, i have now been onto VOSA and trading standards,

          • TheFuelMan Post author

            Hi Andrew,
            Well done for sticking it to them. Most people just roll over and fork out the money blindly. I’ve heard so many stories of this kind of thing happening that I have almost completely lost my faith in dealing with dealerships. I really hope that the trading standards gets a hold of this and sorts them out once and for all!
            The Fuel Man

  • gray

    I put 1/2 talk diesel into 1/2 petrol tank, an 2003 Avensis. Engine stopped after 2 miles. The car got stuck on the Isle of White as a result. It was drained professionally locally and ran OK after but a few days later engine lighte came on – a code P0420for a catalytic converter problem. Consumption now as low as 20mpg perhaps (unconfirmed). MOT is next April. What the best thing to do or think about now – lambda / MAF / … or new converter £1000 – gulp. Have yet to reset the light. Will unplugging the battery do this? Any suggestions? Many thanks

    • TheFuelMan Post author

      Hi Gray,
      It is very possible that the P0420 is due to running the vehicle on diesel. Obviously the diesel doesn’t burn properly and can leave a film over the cat and sensors. This can cause them to fail or show false readings which, in turn, cause your consumption to go up. Unfortunately, due to the fact that this showed up after a few days it is most likely that there was still diesel in the tank/engine after the drain was “completed”.
      You have a few options open to you here:
      – You could have the cat cleaned either by taking it out and manually doing it, or by trying any number of fuel additives which claim they clean the injectors and the cat (I’m a bit sceptical about these as I haven’t personally tried them for this purpose).
      – You could get the cat replaced, and might have to do this anyway if you find it to be damaged when cleaning it.
      – You could possibly leave it as is. I’ve heard of people doing this with the only problem being the increased consumption and possible failed MOT. Again, this is not something that I have tried personally and therefore cannot vouch for its workability.
      As regards resetting the light, simply use the tool which found the code. It should have an option for resetting it. Failing that, yes you could unplug the battery (check this post) but be careful you don’t lock the immobiliser.
      The Fuel Man

  • Laura chip

    More of a question than a comment, as you seem to really know what your talking about, Theoretically, could a diesel car run with no obvious problems for 50 miles, refuse to start after being parked, get started by Breakdown and then drive again with no obvious problems for another (minimum) 50 miles back to dealership, if it had a fuel mix of 15% diesel, 85% diesel in the tank? I’m being told by dealership mechanics I must have put petrol in my car, but my receipt says diesel and have checked with petrol station for issues a their end. I’m worried the garage might be trying to cover a mistake made during the service they performed 5 days prior and trying to work out if what they’re telling me has happened can actually happen. Everyone I know says not.

    Thanks

    • TheFuelMan Post author

      Hi Laura,
      The situation you describe sounds unlikely, although not impossible. A misfueled vehicle will generally show some signs of trouble besides not starting when cold. Normally you will experience sluggishness or the engine missing and spluttering. However, it is possible to get a misfuelled vehicle to run, although this is never a good idea as it can cause damage.
      If you have all the receipts from the fuel you put in then you obviously did not misfuel. Having said that where did you fill up? There is always the chance that the petrol station could be at fault. We’ve been called out by petrol stations on numerous occasions because some joker had put the wrong fuel in their underground tanks. It might be worthwhile googling if anyone else has experienced similar problems after filling up there.
      As a final note, if you dpn’t believe that the dealership is being completely honest with you have someone you know go in to inspect the vehicle (or take it somewhere else for a second opinion – no matter what anyone says you are not legally bound to have your car serviced at a dealership, even if it’s under warranty). The simplest thing to do is just open the filler cap and take a sniff. Any experienced mechanic should be able to tell if there’s petrol in the car just by smell alone.
      Please let us know how you get on.
      The Fuel Man

  • Sarah

    Hello, I was wondering if anyone can help me. I apologize in advance, I bet this question gets asked alot. After putting £8.00 of diesel in my husband’s car today (it’s a golf gti) I went to put air in tyres after. When I was finished, the car wouldn’t start…I tried it a few times, it was dead. To my horror, I realised I had put unleaded in, instead of diesel. Stupid I know.
    I ended up getting a push to the pump & putting £50 of diesel back in, then left it for a bit. It started back up fine, but was a bit jumpy.
    I’m now panicking, as I’m reading how bad it is to try and start it up with wrong fuel in. But by the time I realised, it was too late. :(
    Do you think it will be ok, or am I going to have to call someone out? I’m so cross at myself….a stupid mistake of £8.00 May cost me hundreds of pounds .
    Thanks for reading.

    • TheFuelMan Post author

      Hi Sarah,
      I’m really sorry to hear about your situation. Unfortunately I can’t really give you a definite answer on this. Have a look at this post (the last section of it) and see what you think.
      The Fuel Man

  • mark

    Hi Fuelman,

    Firstly just want to say what an excelent service you run. Its hard to appreciate what anxiety is caused ‘Until it happens to you’ (esp when you read the horror stories.).

    I’ve now got your number in 3 TIMEs for future reference and to forward (for other friends who find thereselves in this indicament). You obviously offer a comprehensive service.

    My story /questions .

    Mistake 1. August Bank holiday weekend i filled up my 2010 audi a5 tdi with 22 litres of petrol (on a 65 litre) engine . My instinxt was to not start engine and get engine drained.

    Bigger Mistake 2: i listened to 3 peoples advice at the gas station and diluted with diesel until overflow tank full. Still leaving me with 30% mix of diesel. – i drove 130 miles through country (not driving hard -around 40-55mph. ) . I also topped up another £15 of diesl on the way to mix keeping the tank at 110% capacity. No real issues at all (the only issue was a minor mistart on one of the 5 occassions a restarted on the journey… drove like usual.

    8 hours after incident i then i googled on my phone .. Read about modern diesel engine working at high presure etc… I then called the AA who for £280 arrived first thing next morning (now about 20 hours after incidents) and drained tank dry supplied half a tank of diesel and emptied in a solution to lubricate and also remove any remnants of petrol. (Is this the equivalent of flushing?). … Over two weeks later i’ve had no issues i’ve kept the diesel topped up ive driven an additional 400 miles most on the motorway and local trips. . ONce back home, I called my trustee local garage ( although bmw specialists) whom said i got lucky and any issues would have have become apparent by now and it wasn’t essential for any more processes and not to worry about it. I asked if i should change my fuel filter they said might be worthwhile considering at my next oil service in 6 months time.

    I’ve since found your most excellent sight, wished I’d called you instead (NOTE: quicker, more comprehensive and cheaper than AA everyone!!!!)

    -I’ve seen your response to Andrew ( on August 7, 2013 at 9:40 pm) whom also seems to have got lucky. Although his seems more extreme (well over 50% mix and -no drain or lubrication). Whats your take on my case? Just a fuel filter change? -should I bring forward the service (is it just oil or full?) . Any computer diagnostics required? what the likelihood that have i done any long term damage?

    Once again, great service you offer and your in my phone book for life under D, P and F! :)

    any response very much appreciated.

    regards
    mark

    • TheFuelMan Post author

      Hi Mark,

      Thanks for sharing your story with us. While no long-term damage seems to have been caused by the misfueling I would think it likely that you have shortened the life-span of some of your fuel system components. Fortunately you got it drained and flushed (by the way, “flushing” is purging the fuel lines, filter, pump and injectors of contaminated fuel and re-priming them with fresh fuel) before you did any immediate damage to the engine, albeit at a rather higher price than most independent companies charge.

      The only advice that I could give in this situation is to get the filter changed. Running 130 miles worth of 30% petrol through your filter will undoubtedly compromise it to some degree. Remember that a diesel fuel filter is simply filter paper glued together. Petrol can start to dissolve/compromise the glue which, in turn, can lead to holes developing in the filter. You should get this replaced as a “just in case”. It is much cheaper and easier to replace a filter than to get a clogged injector fixed.

      I doubt that a full service will do much for the situation but it definitely wouldn’t hurt. You don’t need any diagnostics run on the vehicle unless you have an engine light showing on the dashboard, which I assume is not the case.

      I hope this has been of some help to you.

      The Fuel Man

      • Mark

        Hi fuel man many thanks for the response yes that’s incredibly useful information. Fuel filter changed booked in for December (3000 miles time). With its service and mot. assume thats soon enough?

        Keep up the good work. And i will be sure to Be giving you a call if this ever happens to me again!

        Thanks again.

        • TheFuelMan Post author

          Hi Mark,
          Good for changing the filter. This was the most important thing in your case. The service isn’t really a major issue but it’s good to get it done.
          I really hope you don’t have any further issues with the car and that you never need to call us up :)
          The Fuel Man

  • Craig

    Hi there j put £20 of petrol in my deisel car and drove 40 mils as I got home my injection light come on! I have a Renault scenic will the car be ok??

    • TheFuelMan Post author

      Hi Craig,
      That doesn’t sound good. My advice to you would be to get it drained and flushed ASAP to see if that solves the problem. It is unfortunate that you managed to get a mixture of petrol and diesel that runs because this is generally where your vehicle is most at risk. If an injector has become damaged you could be looking at an expensive repair. However, it could just be that the ECU has picked up a problem with the fuel and a simple drain and flush will correct it. Best case scenario: under £200 to get it cleaned out – Worst case: under £200 for a clean out, and a few grand for a new pump and injectors.
      Having said all that it is very, very rare for you to need to replace anything as most times a drain and flush will solve the problem.
      The Fuel Man

    • Peter Bradbeer

      Dear Fuel Man

      I’ve read through your very informative site (Best on the www) but not read about the presumed after effect of adding petrol to a diesel I’m getting – loud knock at low revs.

      On holiday in France I put in 50 euros of gasoil into the Fiat JTD common rail diesel (nearly half a tank) – at least that’s what it said and my wife confirmed. But when started up, a loud knock at low revs. Convinced I’d put in diesel and having 3 noisy kids in the back drove back to our holiday house. Since then I’ve topped up several times and drove all the way home and down to the west country at the weekend – around a 1000 miles! Car starts fine, runs well – no loss of power but at low revs very loud knocking noise. As there’s rarely such a thing as a coincidence I’m assuming the gasoil was in fact petrol and the engine is now mortally wounded? Strange that loud knocking at low revs not mentioned by anyone else?

      It’s an old car and not worth more than a few hundred anyway but has been a faithful servant –presumably there’s nothing that can be done now i.e. a drain down and engine will seize up eventually? Your advice would be much appreciated.

      Peter

      • TheFuelMan Post author

        Hi Peter,

        Thanks for the compliment.

        As to your situation, I doubt that a fuel drain now will do anything for your car. The main problem with driving a diesel on contaminated fuel is that the fuel pump and injectors are susceptible to damage due to a lack of lubrication. This is made worse by the fact that your fuel filter will slowly degrade as the petrol eats away at the glue that holds it together.
        One thing that you can do, however, is get any sort of additive or fuel flush that will help re-lubricate the engine.
        As to the knocking, this could be cause by quite a few things. Sometimes a full service can help with knocking. Replacing the oil and the filters often does a world of good – especially after a misfueling. That said, probably the most common problem resulting from a misfueling is injector knock: this can be caused by a leaking, clogged or damaged injector. The solution to this would be to have the injector cleaned (using a fuel additive or diesel purge) for minor problems, or complete injector replacement for more serious problems.
        Unfortunately, the knocking could be completely unrelated to the misfueling. In this case it could be any number of problems from cam-shaft to timing. Additionally, a faulty hydraulic tappet will usually be noisy on cold start and often quieter when the engine is hot and should be checked as a possibility.
        If I were you I’d get some additive into the system and run it through. If this doesn’t solve it I would get it into a garage for a service and, while it’s there, I would ask them to pop it onto a diagnostic tool to check if any faults show up.

        I’m sorry that this has been so vague but it is difficult to diagnose a problem without actually seeing it. However I hope it has been of some use to you.

        Please could you let us know what the final outcome is so that our readers with similar questions can get the answers they need?

        The Fuel Man

  • Hamish

    Hi from Australia,

    I accidentally added 0.6 litres of petrol to my diesel car. I filled the 60 litre tank up with diesel immediately. I drove home and there seemed to be no issues. Would you recommend I keep topping up the diesel to continue diluting the fuel? I saw in other comments you mentioned getting an additive into the fuel to help with lubrication. Is there any you can recommend?

    Thanks so much – this website is great!

    • TheFuelMan Post author

      Hi Hamish,
      Thanks for the encouragement. Sorry to hear about the fuel mix-up. Yes, I would guess that you will be fine just continuing to top it up. 1% is nothing much to worry about. As to additives, I would look on the local market to find out what they have. Any diesel additive that says that it cleans and also helps to lubricate the system would be acceptable. To be honest, I’ve even heard of people successfully using 2-stroke engine oil for this purpose – here’s an excerpt from an article I wrote on it:
      There was a lubricity test done (well documented on the internet) which showed that 1:200 2 Stroke Oil to additive-free ULSD (ultra-low sulphur diesel) brought the lubricity of the diesel up to the acceptable motor-trade standard, but they didn’t test its after-effects on the combustion and exhaust systems.
      If you want to try it out I would suggest going for mineral or semi-synthetic JASO FC or better JASO FD 2-Stroke Oil (not FA or FB). These are much less likely to leave a deposit to foul up your emission sensors or DPF. Also, keep an eye on your filter just in case adding it dislodges any carbon deposits in the fuel system which go on to clog the filter.
      A lot of people say that using this as an additive every time they fill up increases their /mpg and reduces smoke and noise. A lot of other people say it made absolutely no difference and that any improvement noticed was purely placebo-like. Very, very few have gone on to mention any sort of problems arising from adding it.
      While the science behind why it works seems logical, I personally haven’t tried it and so can’t give any evidence to support either argument. I might get a bit experimental one day and give it a swing.

      The Fuel Man

  • agripa zinyemba

    womderfull advise.u r a blessing.u hev bn of th greatest help.i put about 7l of diesel in my ml320.am still to drain it out

  • john

    Thank you ever so much you have made me feel much better and a lot less angry with myself. Thank you for providing this service for people especially those of us who know nothing about cars, even put the right fuel in them. I and lots of other people who have used your site owe you a pint.

    Thank you again

  • john

    Hi I have a 1997 1.9 diesel polo and tonight put 48p of unleaded in, ( my mind has gone) when in realised I put £30 of diesel in. Do you think it will be OK ?

    Thank you

    • TheFuelMan Post author

      Hi John,
      I can’t see that being much of a problem. It’s such a small amount that it shouldn’t have much of an effect of the system. To minimise the risk I would get an additive into the fuel to help with lubrication and fill the tank to the brim.
      Obviously the only way to be 100% sure would be to get it drained out – but I really don’t think that will be necessary.
      The Fuel Man

  • andrew

    three days ago I managed to put 32 litres of petrol into my diesel car was about quarter full of diesel beforehand. since then I have driven about 900 miles with no problem I have filled up 3 times since with diesel … do you think I have got lucky and there is little chance of anything bad happening now I know you would recommend a drain but after 900 miles and 3 refills why would any petrol remain ?

    • TheFuelMan Post author

      Hi Andrew,
      I would imagine that you’ve probably put your fuel system through quite a bit of stress. I don’t think there would be much point in draining it now but I would suggest that you get a new fuel filter and use some sort of fuel additive to help re-lubricate the system. If there has been any wear on the pumps you would want to ensure that your filter is up to handling the chaffing and hasn’t suffered any deterioration. Unfortunately, with this concentration of petrol you could be looking at long-term damage which could result in having to replace some parts sooner than expected. My suggestion is to get it in for a full service and fluid change – including the filter – and a lubricant for the fuel.
      The Fuel Man

  • Jordan

    Hi I recently put about 12 litres of petrol into my 2003 ford transit pick up. It already had about 1/4 of a tank in it, I then realised and put about 20 litres in straight away. I drove it all that day and it started fine and ran fine I then on the way home put another 20 pounds into the tank. So there is around a 65 litre of diesel to 12 of petrol do you recon ill be ok? It started ok every time and has ran with some heavy loads of the back too. It’s not my van so I’m a bit scared to say anything help

    • TheFuelMan Post author

      Hi Jordan,
      To be honest, I would get it drained. Although I’ve seen cases where this amount of petrol has not been a problem, I’ve seen more where it has. If you think with the fact that not all the fuel that is pumped up to the common rail is burnt you will have your high-pressure pump moving quite a bit of petrol through it. While this isn’t a strain on the pump at all you might find that the lubrocity (I think that’s a real word) of the fluid travelling through the pump is compromised, which could cause chaffing of the pump and its eventual breakdown.
      Give us a call and we’ll have a chat about it.
      The Fuel Man

  • Don

    Hi my daughter put 68 pence worth of petrol in her Kia Rio 2012 diesel then realised and filled up to brim with diesel without moving the car. She went in to pay and asked if it will be a problem. Was reassured was a miniscule amount and will be fine. She carried on and drove along 300 mile drive with no problems. Went another 80 miles a few days later with no problems and the next day the engine management light came on and the car started losing power in the lower gears. was ok when got going, she filled up with diesel again when tank got to quarter full. As she only had car 6 weeks we phoned Kia and had it recovered to a dealer who are still trying to resolve the problem. She has not mentioned the tiny petrol incident for fear of invalidating any warranty. We sought advice from a mechanic who said it won’t be that that is the problem….not so sure now! Any advice would be appreciated

    • TheFuelMan Post author

      Hi Don,
      Thanks for getting in touch. 68p of petrol is about 500ml. In a Kia Rio that would be about 1.2% of the capacity. I doubt very much that this is the cause of the current engine problems. I also doubt that a fuel analysis by the dealership would even show it up. She has probably saved herself a considerable amount of money by not mentioning anything about it to them as they would, unquestioningly, have decided to replace most or all of the fuel system as a “safeguard”.
      In my many years experience as a fuel specialist I never heard of a case where 1% contamination had caused a problem. That said, it’s not a guarantee.
      It would be interesting to hear what Kia say is the problem with the car. My advice is to not be too concerned about it, but I ask if you can please let us know what the outcome is. I’m sure that our readers would be keen to find out what caused the problem.
      Wishing you and your daughter luck.
      The Fuel Man

  • Reno

    My girlfriend just put 3.8 litres in my 61 plate Kia shortage 1.7 realised then filled the tank with up with diesal will this cause major damage :(

    • TheFuelMan Post author

      Hi Reno,
      It is unlikely to cause major damage provided it has been brimmed to maximise diltion and possibly an additive used to help relubricate the system. However, with a vehicle that is still under warranty I would suggest that, regardless of how much “wrong fuel” is in it, you should get it drained as continuing to drive it on contaminated fuel – if something went wrong – could be very expensive to repair and maintain the warranty.
      Let me know how it goes.
      The Fuel Man

  • Renno

    Hi,
    I use VW Polo – Diesel 1.3 for last 2 years.
    Last week when I was returning home after office, the vehicl was not starting. I took the vehicle to service centre on auto shift. For 3 days only reply recieved from service centre was ‘we are checking’. Later yesterday I recieved a call asking to replace ‘high pressure pump, low pressure pump, rail, hoses, pipes, etc. and it is going to cost me 35k.
    Please advice whether to go for this huge replacement.

    • TheFuelMan Post author

      Hi Renno,
      Did they find out why the vehicle was not starting? Was this due to misfuelling? 35k is a lot more than a new Polo. It is a little unbelievable that they would try charge you for this.
      The Fuel Man

      • Renno

        Thanks for the prompt response. Ya, the problem was due to water mix up with diesel. They have also given me an estimate also. I am totally upset and dono ow to proceed. Please help!

        • TheFuelMan Post author

          Hey Renno,
          I would suggest that 35k is insane – is it not 3.5k?. Is the vehicle still under warranty? Furthermore, what actually is “broken” on the car?
          We know that a vehicle won’t run on water. How much water is in the tank? What happened when it was running on the contaminated fuel? What happened when it broke down – and since then what has been done with the vehicle? With this information I might be able to provide some advise. Or you could just call us.
          The Fuel Man

          • Renno

            Hey Fuel Man, I am really impressed in this lightning response!!! Thank you!!

            It is Rs. 35000/- Vehicle is out of warranty, warranty was for 2 years
            and now it has passed 3 months since then. The list of items and their
            pricing to be replaced is as follows.
            1. High Pressure Pump – 92250
            2. Common Rail – 38330
            3. Injector – 63060 (21020 x 3)
            4. Injector Line – 7530 (2510 x 3)
            5. Injector return line – 6780
            6. Common rail return line – 3900
            7. High pump to common rail – 3280
            8. Fuel Filter – 1290
            9. Pressure regulator filter – 1280
            10. Injector bolt / High press. Pump steady bolt – 300
            11. Labour – 10640
            Total – Rs. 35000 /-

            Service center guys informed that the first 3 spares are being
            provided as a ‘GOODWILL WARRANTY’ and the rest are on chargeable
            basis.

            No idea how much water is contained in the fuel tank. I felt ‘missing’
            twice on the way to the office in the morning and later in the evening
            it was not getting started. After break down, I auto shifted the
            vehicle to the service centre on the same night.

            Is there any mechanism in the vehicle for Auto cut off, if wrong fuel
            / liquid are filled in? Is there any possibility that the pumps get
            worn out as the lubricant (diesel) was not of sufficient quantity?

            1 month back before this incident happened, the vehicle was stalled 3
            kms away from this service centre (I was on the way to Service centre
            for 2nd Service) and had to Auto shift on that day too. Later after
            servicing I got the vehicle back in 3 days and when enquired about
            complaint, they said it was doing well and no complaints were shown
            when they took test drives.

            Now I feel, I shouldn’t have bought the vehicle back without
            rectifying the complaint.

          • TheFuelMan Post author

            Hey Renno,
            I’ve seen this many times before and it seems to be a typical work-sheet for a misfueled vehicle – although this is the first time I’ve seen it for a water contamination.
            Obviously the manufacturer would want to be able to guarantee their parts and therefore needs to replace everything “just in case”. However, the fact of the matter is that it is very unlikely that everything really needs to be replaced. My advice to you would be to have the water drained from the system and the engine cleaned and re-primed with clean fuel. Once this is done you will be able to see what, if anything, actually needs to be fixed or replaced.
            The Fuel Man

  • John

    Many thanks for your speedy reply. Thought i’d share an update for future readers…. Mainly because of the lack of sleep I’ve had the fuel analysed. It must have been fate that the car was booked in for it’s annual service on the morning after my ‘slip up’. The results showed a 3.2% biofuel level which I’m led to believe is quite low even for diesel straight from the pump as up to 12% can legally be added by the supplier. Couple of extra stats here… the VW Tiguan has a 64litre tank & i’d put in 2.15 litres of petrol. So in theory i’d was lucky & had got away with it however to be doubly sure an additive was added (minimal cost) to provide that much needed lubrication the petrol may have stripped away.

    The garage also recommended that rather than drive around and empty the tank, fill regularly to maximise the benefit given by the additive. It’s also been suggested that the fuel filter should be changed in around a 1000 miles.

    Thanks again for your help.

  • John

    Advice please. I drive a 59 TDI VW Tiguan. Popped into the garage with a 1/3 of a tank & managed to put just over 2 litres of petrol in before realising my mistake. Spoke to the RAC who passed the call to their local mis fuelling Contractor. Following a discussion it was deemed ok to fill the tank, then top up regularly for the next couple of hundred miles.

    What would be your take on this & advice?

    • Justin

      Hi John,
      Thank you for getting in touch and for your question. This is probably the area of the most uncertainty and confusion, and the question I get asked most.
      Unfortunately, the problem here is that there are as many correct answers as there are cars in the world. Kate, on the home page, had the same question. Have a look at what I told her.
      Seeing that you only put 2 litres in, if I were a betting man, I would wager that you will be fine – I would still, however, advise that you get a diesel additive into the fuel system to help clean and relubricate it. Obviously the only 100% safe answer is to get the tank and engine drained and flushed.
      The Fuel Man

  • Pete_exe

    Hello Fuel man, I read your whole thread – v. reassuring. I just misfuelled my 2005 Passat TDI 130 – £45 of petrol in a quarter-full tank. I drove about 250m before stalling. It waited overnight before draining and flushing by a local garage. It seem OK on a fresh tank and additive, but seems to have lost performance. I used to get a big power surge when the turbo came in at about 3000 RPM. Now the power seems smoother across the range, OK but duller to drive. Is this possible? Thanks Pete

    • TheFuelMan Post author

      Hi Pete,
      It sounds as though you’ve done everything right so far. It would be a good idea to replace the fuel filter.
      The Fuel Man

  • Chris Davidson

    Hi, I filled my 64 Lt tank of my mazda 6 diesel with approx 60 ltr of petrol then drove approx 3 miles home. Tried to start my car next morning and a huge cloud of white smoke came out of exhaust, car won’t rev past 2-2500 rpms and engine light came on. Have I destroyed my engine?

    Cheers

    Chris

    • TheFuelMan Post author

      Hi Chris,
      Thanks for the question and you will not have caused any serious damage to your engine (or fuel pump, or fuel system to that matter).
      We get asked this a lot, whether on the website, by phone or when our drainers are on a job.
      What you need is a professional fuel drain. We will drain the tank, flush the engine, and entire fuel system, then re-prime it with fresh fuel and have additive on hand which especially in the case of a vehicle that has been run can be good to really clean out the system.
      That’s it – GIVE US A CALL!!

  • clarky

    Hi, I put 44 liters of petrol into about 7 litres of diesl and drove off, the can cut out after about 6 mile. I had a fuel drain and 20 litres in, then i topped up with 40 lites once I had run that through and have done a further 50 miles.Everythng has been fine. However today I thought I felt a loss of power and it seemed to struglle to get past 70. Is this a lasting effect and could I be facing some worse problems. This has happened in the space of 3 days, it ran for 6 hours each day either on tickover or running on each day, cheers

    • TheFuelMan Post author

      Hi Clarky,
      Was the engine flushed, or just the tank drained?
      Provided the car was properly drained, you should be ok, though we do always recommend that you get your car serviced, or at least get your fuel filter replaced after a fuel drain.
      An additive which cleans the fuel lines & injectors can also help in the case of a fuel drain and along with a new fuel filter is a good measure to ensure your car suffers no long term effects.
      The Fuel Man

  • Meshellrc

    Hi,

    I own a prado 2010 GX. Just recently went and accidentally put 9 liters of petrol in my diesel tank that was holding about 40litres of diesel. Then realized my mistake. Then on advice from a friend topped the rest up – which was about 100litres with diesel. Have gone about 400km so far – an average days drive for me in Australia- and still drives fine. Do you think I should just keep topped up to dilute or do I need to drain still? Thanks for your help!

    • TheFuelMan Post author

      Hi,
      Nice to hear from Australia!
      While the odds are very much in your favor, I would recommend a fuel drain. Your vehicle is still worth a lot more than the cost of a fuel drain and not worth risking the unlikely scenario that more serious damage is caused due to petrol in your diesel lines.
      The Fuel Man

    • TheFuelMan Post author

      Hi,
      Nice to hear from Australia!
      While the odds are very much in your favor, I would recommend a fuel drain.
      Your vehicle is still worth a lot more than the cost of a fuel drain and not worth risking the unlikely scenario that more serious damage is caused due to petrol in your diesel lines.
      The Fuel Man

  • Robert

    Well I managed to do this as a result of being busy thinking about something else.

    The one topic that does not seem to have been covered is that the boys over on Disco3 – for Landrovers like mine – suggest adding a litre or so of ashless 2 Stroke Oil into the mix. The Cheapest stuff you can buy. The theory is and there are a few technical papers on this issue that a small amount of 2 Stroke in all Diesel Engines is good for them anyway. That is particularly true with low sulphur Diesel which has less lubricating properties in it than the older fuel.

    In this case though the reasons to add some to the now drained and refilled system is that there will still be some petrol in the mix. So adding a little 2 Stroke Oil ensures that there is a little additional lubricant in there as well. Certainly if you add a small amount to every fill the engine does sound slightly quieter – something to do with how the flame front in the combustion chamber travels.

    • TheFuelMan Post author

      Hi Robert,
      It’s a good question, but something that hasn’t really been officially responded to by the engine makers. While it will no doubt help to lubricate the inner workings of the fuel system there is the inevitable question of what it does during and after the ignition phase.
      There was a lubricity test done (well documented on the internet) which showed that 1:200 2 Stroke Oil to additive-free ULSD (ultra-low sulphur diesel) brought the lubricity of the diesel up to the acceptable motor-trade standard, but they didn’t test its after-effects on the combustion and exhaust systems.
      If you want to try it out I would suggest going for mineral or semi-synthetic JASO FC or better JASO FD 2-Stroke Oil (not FA or FB). These are much less likely to leave a deposit to foul up your emission sensors or DPF. Also, keep an eye on your filter just in case adding it dislodges any carbon deposits in the fuel system which go on to clog the filter.
      A lot of people say that using this as an additive every time they fill up increases their /mpg and reduces smoke and noise. A lot of other people say it made absolutely no difference and that any improvement noticed was purely placebo-like. Very, very few have gone on to mention any sort of problems arising from adding it.
      While the science behind why it works seems logical, I personally haven’t tried it and so can’t give any evidence to support either argument. I might get a bit experimental one day and give it a swing.
      Let me know if you try it and what the outcome is.

  • Leif Hansen

    Thank you very much for your prompt reply. Based on your relply I will monitor the situation carefully and at the first sign of any trouble I will get a complete drain down.

    Thanks again.

    Regards,

    Leif

  • Leif Hansen

    Congratulations on your great website. Unfortunately like many others I have managed to misfuel by adding two and a half litres of petrol to a 70 litre diesel tank (Chrysler Grand Voyager CRD) before realizing the mistake. The tank has been filled with diesel so I now have a ratio of approximately 28:1 diesel to petrol. The car is running nicely without any problems or unusual noises, however, will this cause any problems in the future? It was my intention to continue to add diesel gradually on a regular bases unless you recommend differenttly.

    Tahnks very much for your advice,

    Leif Hansen

    • TheFuelMan Post author

      Hi Leif,
      Thanks for the question.
      If it were me, with a ration of 28:1 i would fill the tank with diesel and top up as you have done.
      However, there is no guarantee and the risk is it brakes down with a full tank (so more money lost on fuel) or petrol in the diesel lines causes more damage in the long run.
      In my experience, you will be fine, but as a ‘customer’ I would always suggest if you really want to be sure, get a fuel drain.

  • Arnold Saber

    Hi Fuelman,

    I accidently filled about 60litre of petrol in my Mercedes Benz ML 280 CDi. There was about 1/2 tank of diesel in it. As I had a long drive to a very urgent meeting I didn’t pay attention to a little knocking that occured during the drive. I realized there was something wrong when I had done almost 200 – 220 kms, but the car did not stop, neither was there any indication on the panel. I filled in the tank to full again and drove back. There has been no issue with any firing or sound of the car. I haven’t seen any white smoke from the exhausts. I have realized it takes a little longer to start on, but other than this there has been no complaints with the car. I am going to get it drained ASAP. I must have driven about a 1000 kms now, do you recon there would be a lot of damage done to the engine???

    • TheFuelMan Post author

      Hi,
      Thanks for contacting me and it sounds like you’ve been very fortunate so far.
      While I can’t guarantee anything, provided you get the vehicle professionally drained, it is unlikely there will be any long term damage to your car.
      We do advise you get the vehicle serviced, or at least the fuel filter changed after a drain also. This help in the longer term.
      Call us on 07514 409700 and we can get someone to come to you and do a drain. We have nationwide coverage and are very competitive with prices.
      The Fuel Man

  • harry

    Hi,

    I put 35 litres of unleaded into a tank containing 15-20 litres of diesel. The car is a 2008 Golf Match 1.9 TDi. Drove it just under a mile, then it stalled. Started it again, drove about 2 yards and it stalled again. Realised what I had done and called the AA who drained the tank. Filled up with diesel, drove 300 miles, then filled up with diesel again as advised by the AA. The only problem is that I’m now losing power – I put my foot to the floorboards and it accelerates really slowly. Could this be caused by the unleaded petrol?

    Thanks for all the great information on your website!

    Harry

    • TheFuelMan Post author

      Hi Harry,
      Assuming there was nothing wrong with it before the misfuel, it seems like there may still be some fuel in the system, though in my experience, the AA are usually very good at this.
      As you have already had the fuel drained, you can either replace the filter and/or get a service, continue what you are doing with filling the tank and see if it improves (though may take a while), if that doesn’t work, give us a call and we’ll get you sorted.

  • Richie

    Hi,
    My wife has filled the tank of our new Kia Sportage diesel with unleaded and drove it home, less than halve a mile. I then drove the car and noticed that it was not driving correctly, I suspected misfuel.
    I have just got it drained by a professional company and they have used additives, additionally I have now put 30litres of diesel into the car.
    It seems to be driving ok.
    Is it worth me replacing the fuel filter? The company recommends it.
    And
    Would the dealer be able to detect it now I have had it drained?
    P.s found your website really informative, seems to be a lot of scaremongering on the net.

    • TheFuelMan Post author

      Hi Richie,
      Thanks for the comment and glad it’s now running well.
      We do recommend that you get your car serviced, or at least replace the fuel filter after a drain.

  • Tommy monahan

    Recently I filled a Skoda superb with 15 litre of petrol then 40 litre of diesel ,I then drove for 120 miles and filled the car again ,drove a further 120 miles and decided to drain the tank.at this stage the car seems to be driving as well as ever, However I have just done a fuel check and discovered that I am now getting 2 miles per gallon less then I was previously ,would this be what you would expect

    • TheFuelMan Post author

      Hi Tommy,
      If you’ve only drained the tank, then there is most likely still petrol somewhere in the lines or in the filter.
      I would suggest at the very least you service the car, or even better – get it professionally drained.

      • Tommy monahan

        Hi Fuel man
        Many thanks for your reply, At this stage the car has resumed its previous fuel efficiency and is running as it was before I filled with petrol, I have also changed the fuel filter as advised.\once again thanks very much for the advice it was very helpful

  • Bill kerswell

    I used to run a Bedford cf van on diesel/petrol mixture from a local garage for years so had free fuel! They were gla to get rid of it but it never hurt the Bedford engine which actually ran better than pure diesel ,and I drove it flat out ,foot to the floor,maybe the old Opel designed engine was designed to be multiple fuel? is there any other engine that will run on petrol diesel mixture in unknown quantities?

    • TheFuelMan Post author

      Hi Bill,
      Interesting question. I have found that the older big diesel engines deal with it better than most, assuming it’s mostly diesel in the tank.
      Unfortunately, you won’t know for sure until you try it on the vehicle, I’ve had a very old Mercedes 300d which did ok, and an even older Land Rover 110 that also did ok.
      Just make sure the vehicle is worth less than a tank of fuel as almost every vehicle reacts differently and I wouldn’t want you to cause terminal damage to your pride and joy.

  • Lorcan

    Hi there,

    Very informative website.

    I did the same as most people here – petrol in a diesel, got about half a mile and conked out. Managed to get towed to a garage, get the petrol drained out and the car now seems to be running fine (2008 Seat Altea XL 2.0).

    I was wondering about the likelihood of long term damage? Also, I have a 12month warranty – if something else goes wrong will my dealer be able to detect that I petrol in the car and not honour the warranty?

    Many thanks,

    Lorcan.

    • TheFuelMan Post author

      Hi Lorcan,

      Thank you for you comment.
      Glad you have found the site informative.
      In terms of long term damage you are not looking at any. If the car has been drained and the correct fuel put back in, the car will run fine. Even in extreem cases where the car has filled to capacity with the wrong fuel and then driven until it stops driving any more. The car will still be able to be drained and the problem corrected. The car will not be left with any long term damage. There will be no sign of the fuel error left in your car. The only exception is if petrol was put in a diesel car and the error was not dealt with quickly, the petrol can start to erode the hosing in the diesel car.
      I hope this info helps!
      Hopefully others can post their experiences to and you can get more comments.

  • John

    Thanks for your considerable write up on miss fueling. Can not think why I would do such a thing, but I have saved you on my Favourites just in case !!

    Can you advise if there is a way to visually check if a petrol car has been missfueled with diesel, I am buying used soon.

    From your comments it would be present in the engine oil ?

    How do garages check ?

    • TheFuelMan Post author

      Hi John,
      The two most visible ways of seeing whether a petrol has been misfueled with diesel (assuming it’s still running) in my experience is it will be smoking heavily through the exhaust, particularly when starting, or when pulling off. Another thing that will happen is that some of the diesel will not burn and will start to make it’s way into the engine, this dilutes the oil and will add to the level of oil already there.
      But, if a decent amount of diesel has been put in, I would expect the vehicle to struggle to start or drive at all until drained.

  • Rach

    Hi, I’ve accidently put £5.00 of petrol in my diesel car, thats about 3 litres I believe, I drove home and drove to a garage where they told me to put sone diesel in the car to dilute the mixture. I did that and drove home, the car seemed to be driving ok, I’m just scared as to what I should do? Please help

    • TheFuelMan Post author

      Hi,
      This is the million dollar question, from my experience it has a lot to do with the type of car, I would say if your driving it and it is not making any difference then you may well get away with it. Try topping up the fuel whenever you can so you are constantly diluting the wrong fuel. If you want to let me know they make and model I may be able to give you a more confident answer. I do ask people who have done this to write a comment later on the website letting us know of any effects.

  • Paul Wales

    Put just under 2 litres of unleaded in a Toyota Verso diesel, topped up with 40 litres of diesel and then drove 150 miles before topping up with diesel again.

    Car sounds and drives fine. Would I *probably* be ok to just keep topping up until the petrol is just a trace?

  • Brian Edy

    Hi – Last night, I accidentally filled about £1.20 of diesel into my petrol Rover 25 (2002 model) – the car was already half full so I have added about less than a litre.
    I decided to drive home and got home OK, without any problem – Because this is such a small quantity seems I have 2 options:-
    1. top up with petrol and chance it, keeping an eye on the oil level
    2. Drain the tank
    What do you recommend
    Thanks

    • TheFuelMan Post author

      sorry, but a drain is your best bet, or the very least an oil and filter change, diesel causes a world of greif in petrol engines, clogged cats, gungy spark plugs, mucky air flow mass sensors…

  • rochie

    once i made this stupid mistake, i put 9 ltrs unleaded on my BN marc cdi 220. as i realised, i made a stupid judgmental error, where as i should have called someone to drain the system, instead i filled it up with diesel and ran fro 20/30 miles and when it reached around three quarter , i filled it up with diesel again, and ran for another 30/40 miles and filled up with diesel again. all these time the diesel i was using was shell v power. there was once i left the car parked for few hours and when i tried to start it , it started but coughed a bit, then it was all okay. so after few days , i used redex fuel system cleaner, and then filled up the tank again with diesel. so far i didnt faced any trouble, but i am wondering whats gonna happen when i take my car to the dealer for servicing… since i havnt changed or done anything about it..

    • TheFuelMan Post author

      sounds like you dealt with it quit well,

      The dealership check for petrol in diesel on every diesel car serviced, a misfuel earns a dealer between 6 and 9K, and they DO check.

      I would suggest you drain it, completely, petrol can be traced in diesel cars in microscopic quantity and its not worth having a dealer threatening to cancel your warranty over.

  • Louise

    Agghhh, please help! I have mis fuelled my diesel BMW one series 06, with ten litres of petrol. There was only about 8 pounds worth of diesel in and it drove for ten mins then died.
    The car was left for a day and a half until the garage could collect it and after a drain and a changed filter, the garage are saying the car won’t start and it is possibly a new back pump??? At £900 !
    Can anyone shed some light on what to do next to get the car working again as I have read that the fuel pump would not have been damaged? And I’m not letting them change it for nothing. Any ideas?
    Thank you.

    • TheFuelMan Post author

      Hi Louise,
      I have seen one instance of a fuel pump needing to be replaced but I would say that 99 times out of 100 fuel pump problems after misfuelling, once a proper fuel drain is done you will find the fuel pump running perfectly fine. The one time it did need fixed I strongly believe the fuel pump was on the way out regardless. Give us a call and we can come over and get a proper fuel drain, if in the very unlikely case that you need a fuel pump I would be happy to give you a discount on the fuel drain.

  • Gerrie

    I recntly purchased a Hyundai iX35 2.0 GLS demo with very low km’s. The manual says one should not fill the fueltank to the brim. I am anxious to measure the fuel consumption. Can I do damage to the car if I do fill the tank to maximum capacity and is there another way to accurately calculate fuel consumption?

    • TheFuelMan Post author

      hi,, if you fill it from empty to full you should get a good idea of what it is using on the next fill, just stop filling as soon as it cuts off the first time

  • Nick

    Hi
    Recently put wrong unleaded in my 06 Focus TDI. Drove for three miles before realising. Was towed away by AA before they drained the tank. Have done around 300 miles since without a problem but am now having trouble starting, is this normal?

    Thanks

    • TheFuelMan Post author

      It does seem unlikely that this will have been caused by the wrong fuel, sometimes some strain can be placed on the starter motor when getting the car going again, this can be prevented by using easy start.
      I hope that helps.

  • CursedTeen

    so my gas light came on and I went to the local Shell, not realizing they have gas pumps on one side and diesel on the other, the diesel side was the one I drove up too. I put 20$ in and drove to a friends, after we were all done hanging out I went to start the car and the brake seised up and the gas pedal wouldn’t work. An indicator light came on telling me to contact my dealer, Its Christmas Eve and I’m in debt about 500$ for an engine flush, just thought I’d share.

  • Templor

    I put about half a tank of petrol into my diesel which was showing just above red line. Drove 33 miles without any juddering other than at the very start. On trying to restart the engine stalled. Got it drained and put lube in with fresh tank of diesel. Will having driven for this distance completley ruin the engine? Its a Insignia SRI and like many of the above people reading other forums has given me a severe headache thinking about potential repair costs! Will definitley add your number to my phone having had this happen in case it reoccurs.

    Many thanks,
    N

    • TheFuelMan Post author

      I have dealt with so many vehicles that have been driven well in excess of 33 miles on a wrong fuel mix, I am yet to hear of any lasting damage once a full fuel drain has been done.
      The worst thing you can do is leave petrol in your diesel engine for a long time as it will deteriorate your pipes, I have explained this on my website.

  • A samad

    My car dash board showing the engine light and the car making a jerking noise. My wife may have put wrong type of fuel. Diesel instead of unleaded petrol but she can’t remember. Please let me know if she has misfiled and what shall I do now?

  • graham marshall

    My 2008 2.7 diesel jaguar xj has a fuel starvation problem. The jag dealer says that the tank & fuel line is heavily contaminated with metal filings and one of the fuel pumps is breaking up. Needs a full fuel line replacement (£9.5k – ouch!).
    I have owned the car for 2.5 years, covered 27k miles of its 50k miles and never mis-fuelled.

    The car is subject to a premium extended warranty – is the fuel pump problem likely to be a normal part failure (or consequent upon some other issue)?

    Thanks for any comments/info

    • TheFuelMan Post author

      Hi Graham,

      Jags are lovely cars, but having had and gotten rid of a couple, I can’t vouch for their reliability, it does not sound like a misfuel problem but in your case you could send off a sample of your fuel for as full lab report to cover yourself. I dont have details of who does the lab reports to hand but it costs about 150 quid and is very accurate.

  • John

    Hi Fuel Man,

    I am very happy to have found your website. My wife put about 30 litres of petrol in our 2012 Hyundai accent CRDI and drove 15 kilometers home. There was about 5 litres of diesel in it and she said that it conked out about 10 times. I sent the car today to a local mechanic and asked to be drained, flushed and for a new filter just to be on the safe side. I am waiting to speak to them tomorrow to find out what’s happening. I sent to the local mechanic instead of the dealership hoping that they will be more practical, honest and less expensive.. I am anxious to sort it all out!!

  • Dean Sard

    Hi, thanks for this great and informative website! Today i filled up just under 3 litres of petrol (£3.80) in my wife’s 120d bmw (2005), as soon as i realised this i put £35.00 worth of diesel and drove it 30 miles no problem, I have just put another £20 worth of excellent diesel from esso. Would this be ok?

    • TheFuelMan Post author

      hmmmm, I know its not what you want to hear but a fuel drain would not do any harm, a little bit of petrol can go a long way to corroding plastic diesel fuel tanks, fuel lines, injector seals etc.. Its a calculation of cost of drain versus likely-hood of damage, and cost to repair damage versus your relationship with lady luck, my professional advice would be to drain it, but if in doubt, toss a coin.

  • Ashish

    Hi,

    I own a 57 reg BMW 730d Sports. Accidentally put 15 liters of petrol in it last night. I did not turn on ignition or start the engine. While still in the forecourt of the filling station I called a local fuel drain company. On arrival the technician adviced me to turn the ignition ON inorder to get the car into Neutral to move it(Didn’t work anyways). The ignition was turned on although the engine wasn’t started(I understand this starts the pre pumps). After switching the ignition OFF the tank was drained throughly (The fuel filter wasn’t changed) and filled with 20 liters of diesel from a can. The car was then started(took a few minutes), moved a few meters to the nearest filling pump and topped with full tank of diesel(70 liters). I drove it home (0.5 miles) and it hasn’t been started since. I am bit concerened that the short period for which the ignition was switched ON might have caused circulation of disel petrol mixture in the fuel system and am scared to start the car. Any advice will be appriciated.

    Regards,
    Ashish

  • Chris

    Hi I put 10 pounds worth of petrol into my 2007 audi a3 1.9 tdi. I then filled the take with a further 60 pounds worth of diesel, and since then another 15 pounds worth of diesel! The car runs as normal as ever, only issue now is that when the engine is warm it takes a while for it to start like in the video you have posted, when it is cold it starts first time! I have taken to a garage and there can’t find any codes on the diagnostic could any body tell me what this fault might be, thanks.

    • TheFuelMan Post author

      It sounds like you need to drain it, misfuel creates havoc with engine management systems, it’s odd that it starts from cold but not hot – Ive heard of that before on VW/AUDI engines after wrong fuel. best do a fuel drain.

  • Michael

    Hi,

    My GF just accidentally put 15 litres of unleaded to my BMW E90 2 litre diesel, then immediately without starting the engine toped it up with 40 litres of diesel. I recon there is 15 litres of unleaded and 45 of diesel. That gives 1:4 ratio. Should I just add a bit of engine oil to lubricate the pump or … DRAIN?

    What do you recon?

    Thanks

    • TheFuelMan Post author

      Hi, Sorry to hear it, do not put engine oil in the tank, if it was that easy I would put engine oil in all my mixed fuel (2000 litres a week) and voila! diesel!
      It needs a drain,a full one, and it’s got a saddle shaped tank that hangs over the propshaft on both sides, if your feeling brave give me a call and I talk you through doing it, or we could come and drain it. hope that helps

  • Mrs H

    Hi,

    My husband recently (Sunday) put £17 worth of petrol in my NEW diesel Mercedes. He didnt realise until he drove to the sweet shop and tried to restart (approx 1 mile) After trying to start a few times he realised his mistake. The car was towed to our house. The following day it was drained by (ex mercedes mechanic) and filters replaced. I’ve just received a phone call to say it is ready and fine. Is this likely to cause me any further issues? I am just anxious as this is a new car etc…

    Many Thanks

    • TheFuelMan Post author

      Hiya, I think you dealt with it very well, you can’t go wrong with an ex mercedes mechanic and in my experience it will be fine.

  • Eve

    Hi, just a quick question, my car went in for body work repairs after an accident and was refuelled by the garage with about £5 worth of “fuel”. I have a vw golf 1.9 TDi. There was approx half a tank of diesel in before they topped up.

    After about 20 miles of driving, it now sounds bloody awful (lawn mower like), and I’ve noticed a small amount of smoke.

    Given that the guy who returned it to me and refuelled it was a little bit “Tim nice but Dim” I’m beginning to wonder if he used the wrong fuel?

    • TheFuelMan Post author

      Hi Eve, it sounds like dim tim may have well have gotten confused at the pump, I recommend an olfactory analysis, (I usually charge 300 quid) for this but I can tell you how to do it yourself, firstly open up the fuel filler cap of another diesel car that has not been misfuelled, have a good sniff, it will smell oily and a bit “stale” then pop open your filler cap and have same sniff, if it smells anything like petrol… go and ask tim for a receipt (and check the time and location on it fits with his story about filling it up), the worst case scenario is it will need a fuel drain. call me if you have any questions.

      • Eve

        Thanks for the very quick response, I’ll check first thing tomorrow. I’ve since put £35 of diesel back in and the noise is still pretty bad, almost like its misfiring. I guess there could be a mechanical fault and I’m clutching at straws, but something doesn’t seem right!

  • George Melville

    Greetings from Australia
    Was standing at the pump and realized I had put 10 liters of petrol into my Vito van. Tried to siphon it out but there was not enough in the tank kept sucking air.

    Fortunately there was a boat shop next door to the service station and the guy had a unit that looked like a pump up garden sprayer but it worked in reverse, it sucked.

    Pulled about 10- 12 liters out with this great bit of gear in 5 minutes. Filled the tank to overflowing and found I had put in 64 liters and the most I have been able to fill in the past has been 67 liters. Van runs fine so I was quite happy but still concerned found your great site and you have put my mind at rest.
    Thanks again

    • TheFuelMan Post author

      Another Aussie!, you sound like the resourceful type, well done, and yes your VITO will survive, the engines on those things outlast the bodys by 10 years anyway so no harm done!

  • Shayne

    What a great site and hello from Australia! I have, for the first time, put petrol in my Mazda Bravo Diesel.

    I put 6-7 litres of petrol into the tank which probably only had 10 litres in it. The truck started fine and I drove it around 40KM without problem – still didn’t realise I had put petrol in it. After this first trip, I left the truck for around 15 minutes and tried to start it again. It took a few goes, but eventually started and ran fine. After driving it again for around 20KM, I finally woke up to the fact that I had put petrol in it. I stopped driving it at this point.

    So, I will drain the tank and fill with diesel in the morning (24hrs after putting in the petrol). Do I need to flush the fuel lines etc. or will the contaminated fuels run through as I drive the truck over the next few days?

    • TheFuelMan Post author

      Thanks Shayne, its nice to have visitors from afar, if you drain it out completely it should be OK, you won’t have to flush it thru, my suggestion would be, drain in, fill it to the top with diesel, drive for 50-100 km , then change the diesel filter, I don’t think you will have done any long term damage.

  • Gaurav Sharma

    Hi
    I put 3.5 litres of Petrol in my Hyundai i20 Diesel. Then I added 38 litres of diesel in it to dilute the petrol. I drove almost 100 miles since then and not faced any problem. Although sound of the engine is a bit on higher side (I think or may be Im thinking too much) Please help.

  • Callan Thompson

    Just put £8 worth of petrol in a 58 plate corsa drove 2miles then put £40 worth of diesal filled it from pretty much empty will it be ok or should I drain

    • TheFuelMan Post author

      Hi, call us for price, depends on where it is and if it was driven, hybrid cars are VERY sensitive to wrong fuel and I recommend a drain, damage depends on how far you have driven it

  • John Coyle

    Hi,

    I put £30 pounds of petrol in my Seat Leon 2.0 supercopa. I then chanced my luck and filled it with diesel and drove home about 20miles.

    Since reading comments on the Internet starting to really panic will a drain of the tank be all that’s required.

    Cheers john

    • TheFuelMan Post author

      Hi John, yep theres some scary reading on the internet about misfuelling, most of it is ill informed hype from armchair mechanics.

      All you will need is a drain & flush, call us to arrange

  • Liz

    Two and half weeks ago I put 30 liters of Diesel on my car. It is a 55 liters I think. It still had some petrol in the tank and then I put 15 more liters of petrol to completely fill it out.
    It is manual transmission. I was advised to just continue driving it, of course it was hard to get it to start, but once started and get it to 30-40 km/hr it was working normally.
    It’s been 1000km since that incident, and the “only” symptom that remains is that the engine sounds like a diesel engine all the time even when idle. What do you think could be causing that noise and what would be your recommendation? Usually dealers where I am want to take advantage of this kind of situations and I’m afraid this would not be an exception, so I would like to at least show them that I know a little bit of what could be the issue.
    Thanks so much!

    • TheFuelMan Post author

      Hi Liz, I strongly recommend that you stop driving your car now and get the OIL drained out and replaced as well as the fuel.

      Diesel does not burn completely in a petrol engine and finds its way into the engine oil, this raises the level of the engine oil (now diluted with diesel) to a level that can destroy the engine very quickly. not to mention the lack of lubricating qualities in diesel as far as engine components go.

      Hope it works out ok for you!

  • Dan

    Hi Fuel Man,

    I have a brand new 2012 hyundai ix35. Yesterday I put 4 litres of petrol in the tank. panicked rang a few people who said fill the rest with diesel (i had to turn it on to get to the diesel pump though) . I drove it for about 2 minutes around the corner to work when it jolted a little. Rang my mechanic, got it towed to him, where he drained replaced filter and filled with diesel. Drove home fine after this. To scared to drive it again though. Have I done damage? I just don’t want to loose my 5 year warranty.

    • TheFuelMan Post author

      Hi Dan,

      I doubt you have done it any lasting harm and it sounds like you did the right thing getting a fuel drain.

      If you want to be on the safe side stick a good dose of injector cleaner in the tank AFTER you have depleted everything in it and refilled it to the top again.

      Take care

  • Fabio

    Hi ya,

    I was wondering what the regulations are about misfueling, as far as, where is it safe for you to drain the engine because I’ve heard things like you cant drain an engine on the motorway and I just wanted to double check information like this?

    • TheFuelMan Post author

      It is not safe to do any form of repairs while on the motorway, always safest to tow the car off the motorway before commencing a fuel drain. You can find the regulations your looking for on the DVLA website.

  • Giles

    Hi there !

    Have put 2.25 litres into a 2.0 litre Astra CDTI ( hire car from our car being written off- yes, petrol! ) – have filled with diesel, (55 litres +) driven 50 miles – all ok and no indication of any problem – however, should I get the tank drained ? Or should I drive all night to burn away the mix…..? What would you advise ?

    • TheFuelMan Post author

      As much as you won’t want to hear it I would recommend a fuel drain, hire companies have an uncanny ability to detect misfuelling and they rarely miss an opportunity to add punitive charges

  • Andrew Scott

    My wife misfueled her 2010 diesel range rover,the main dealer collected it and said it needed £8401.00 of repairs.we contacted a local 4×4 specialist who recovered car and drained it for £400. That was about 10,000 ago. Both turbos have failed and the dealer is saying this isn’t covered under warrantee because of the misfuel. Is this correct?

    • TheFuelMan Post author

      Hi, firstly sorry to hear it, doesnt the 2010 rangerover have an “anti misfuelling” device in the filler cap?

      I doubt very much the turbo failure and the fuel situation are related, misfuel can occasionally damage fuel pumps, and injectors, but I have never heard of a turbo failure. I suspect the main dealer is exacting revenge for not getting the £8401.00 they wanted for the misfuel. I suggest you ask the local 4×4 garage for advice regarding how to deal with the main dealer, they may have encountered it before, and I would not rule out spending a few quid and raising a small claims action against the dealer for the cost of repairs, whatever way it turns out please let us know how it goes.

  • Kristy

    Hi Fuel Man. Bless you for this website and for being so kind to share so much of your knowledge with those of us unfortunate enough to make the mistake of using the wrong fuel!

    I have a ’08 Toyota Auris diesel engine. Last week I absent mindedly put 8 litres of petrol into my fuel tank. Going off advice I had heard, I then finished filling with the correct diesel fuel. This meant about 12-15% of the fuel in the tank was the wrong type. My husband and I felt confident that it would be okay, as some of our friends had done something similar and didn’t have any lasting problems. However, after a week and about 100 miles of driving with this mixed fuel in the car, I’m getting worried, especially because now the car is sounding awful, like someone has put a bunch of nails into the exhaust and it’s not driving smoothly (though it’s still mostly starting up okay). After finding and reading through your very helpful faq webpage, I’ve concluded that we should most definitely drain the fuel tank and refill with fresh diesel.

    My questions are: Is there a chance we’ve done lasting damage to our car?
    Is draining the fuel something we could attempt on our own? My husband feels confident that he can siphone it out on his own.
    Would this be enough, or should we have a professional flush out the entire system? Money is really tight right now, but I don’t want to risk having costly engine repairs further on in the near future.

    Many many thanks in advance for any advice you can give. It’s good people like you that keep the world going around!

    • TheFuelMan Post author

      Hi Kirsty,

      hmmm, just had a look, the Auris has a 55 litre tank… 8 into 55 is… 14.5% which would cause the kind of trouble your having.

      Theres about half a litre in the fuel system, and the rest is in the tank, since you have already driven it a 100 miles I wouldn’t bother draining the system for the 60 ml of petrol left in it. which will burn off in the first 5 miles anyway.

      He could do it himself, I suggest he lifts out the back seat and goes into the tank from the top access hatch, thats the best way to drain a tank as you can see right into it and get every last drop, once its empty put in 5 litres clean diesel, straight to a petrol station and fill it all the way up.

      I strongly suggest a new fuel filter, they are easy to change and cost 10 quid or so, petrol sometimes dissolves the glue that holds the filter system together inside.

      If he needs talked through it tell him to call me, I also did a post a while ago on here with pictures about how to drain from the back seat that should help.

      Take care

      • Kristy

        Thank you for your prompt response! Feeling much better about attempting to do the drain on our own. I’m wondering though, what do we do with the fuel after we have it drained from our car? I’ve phoned a number of garages, and my local council, but no one is willing to take it or knows where or how I can dispose of it.

        • TheFuelMan Post author

          hi again, pour it into the waste oil recycling bin at your local tip, you need 2 x 20 litre jerry cans, or if you know someone who makes biodiesel they will take it from you,

  • Martyn Sansom

    Help please..
    Something about becoming older?
    I have owned a 1.9 diesel Galaxy 130psi on a 2005 plate from new.
    For seven years I have always put diesel in until 2 months ago when I put in 5 litres of petrol before realising. Advice at the time was fill it up with diesel (and it took 60 litres) and you should be O.K. and thankfully it appeared I was.
    I was advised to fill up at ‘half a tank’ at a time from a garage that supplied fuel with addatives – not availailable from Supermarkets. This was done twice and all seemed to be well.
    Today filling up from nearly empty with an ‘Ultimate’ fuel I realised that, being in a garage I was not used to, I had put 18.34 litres of ‘Ultimate’ petrol in the car. Completely embarrased and upset I added a further 47.2 litres of ‘Ultimate’ diesel and drove the 2 miles home, £99 the poorer.
    What are my chances of my surviving this latest incident?
    Please let me know, and advise off line if need be, the cost of remedying the situation.
    I am base in Bedford.

    • TheFuelMan Post author

      Hi Martyn,

      Sorry to hear it…

      The ford 130PSI engine is highly tuned and they are sensitive to being misfuell’d, that said 2 miles certainly will not kill it so don’t go buying a new engine and fuel pump from Ford just yet!

      It most likely will have a hard time starting again from cold, and may not start at all, this isn’t a symptom of catastrophic damage it just means its not getting the fuel it wants.

      I would definitely suggest a fuel drain, we cover Bedford and the cost would be £150 + VAT, we can also supply fresh diesel at pump price to get you back to the petrol station. alternatively if you are mechanically minded and fancy having a go yourself give me a call and I can talk you though it

      If you have had the car for 7 years and this is your first misfuel you are doing better than most!

      Take care,

  • D Briden

    Hi

    Did ‘the impossible’ this morning (had a diesel for 9 years) and filled by VW Polo Bluemotion(!) with unleaded ;-( – Had about 2/5’s of diesel still in it.

    Gentle drove 2 miles before I noticed a very slight ‘chug’. Pulled over and called the AA.

    Did not cut out and no light came on.

    Nice chap emptied tank and flushed + added fuel and additive.

    Car started after a few attempts (air in system) and I then gentle drove it 5 miles to station and topped up with diesel – car felt fine and also afterwards (drove gentley the extra 30 miles to work!)

    Have read the instructions from the AA about taking to dealer – chap said that it was what they had to put and that from the looks of it (good amount of diesel still in the tank, driven 2 miles behind a lorry and even that was coasting some of it + no light and only one ‘knock’ the car should be fine…)

    What do you think…?

    Did I learn a lesson and get away with it….. HELP – I still feel ‘quite sick’ about it…

    Regards

    Damian

      • D Briden

        Thank you – that makes me feel slightly better about it…..

        I just went for a walk this lunchtime and started her up – she did first time, no hesitation or any lights on dash…

        I would say that I’ll know better next time – still not sure how I managed to though this morning….

        Thanks again, I feel better now about my 65 mile commute home later!

        Excellent report by the way….

        Regards,

        Damian

  • Katharine Hesketh

    Hi,
    We’ve just bought a new Honda CRV (2012) and are still breaking it in. However, on our most recent trip, we made the mistake of putting in a small amount of petrol. It is about 60 pence worth (around half a pint) and the tank was filled up with diesel afterwards. Will we need to get it seen, even with such a small amount?

    Thanks!

    • TheFuelMan Post author

      Hi, I think for that amount you should be ok, as a suggestion you could leave the fuel cap off overnight and most of the petrol would fume out, leave the fuel cap on your drivers seat so you dont forget to put it back on before you go anywhere.

  • adele

    hi i put 7 litres of petrol in my 2003 tdi golf and straight away i put 17litres of diesel (i remember a mechanic telling me to dilute misfueling) i drove 12mile round trip perfectly fine just a bit of a dodgy start up when i nipped in the shop any advise would be a help

    • TheFuelMan Post author

      Hi Adele. advice is what I do best so you came to the right place, you kinda did the right thing as an immediate fix but from a cold start you will most likely get big greif if it starts at all, I would strongly recommend a full fuel drain – diesel golfs have plastic tanks and rubber fuel lines, petrol golfs have specially treated tanks and steel fuel lines, to cut a long story short you end up with rubber soup after the petrol disintegrates the rubber and plastic that was never meant to accomodate petrol, which causes big problems for the fuel system and engine, I think what I am trying to say is get a fuel drain, the AA and RAC offer a small discount to members for fuel drains and there are plenty of other fuel drainers out there who charge less and do a great job

  • Carl

    Hello

    I have a 2005 1.9cdti vectra estate. The car had a fuel in the car and I stupidly put a litre of petrol in. I instantly filled the car with diesel. Should this be ok?

    Carl

    • TheFuelMan Post author

      Hi Carl,

      A drain would always be the best option but a litre won’t immediately stop the car from running, it may do harm in the long run to the tank and fuel lines

  • Mike

    Hi
    Wife filled up ’05 Freelander TD4 for second time in a year with petrol and drove until it stopped both times.
    Drained both times by main Stealer, babies in car, AA recovered, I was at work, too hard to try and do it any other way…
    Car was not great on cold starts before but now its horrible with tons of white smoke when it finally runs and clears.
    Would appreciate any thoughts.
    Great site by the way
    Many thanks

    • TheFuelMan Post author

      Hi Mike,

      hmm, it sounds like it could be a few things, from the starting symptoms it suggests it still has petrol in it, freelanders have a dual tank system and maybe only one tank was cleared, or there could be a sensor playing up in the air flow or exhaust system.

      The first thing you should do is sniff the fuel at the filler cap to check for petrol, if the fuel drain was done properly it will smell like diesel, oily and sour, if it smells of anything other than diesel then I would suggest another drain (back to the dealer and done at the dealers expense).

      Let me know how it goes,

  • Claire Best

    Hi, I misfuelled yesterday and had a drain done today. They gave me £15 worth of petrol in the tank. My husbands taken the car out tonight, driven 20 miles and now it won’t restart!!! Is this a complete disaster?? Thanks.

    • TheFuelMan Post author

      Hi Claire,

      No, not a complete disaster, £15 isn’t much petrol these days, about 11 litres, which is why we always supply 20 pounds of fuel with our drains.

      Either the car ran out of fuel, which is not inconceivable if the tank was drained to nothing with proper fuel draining equipment, sounds odd I know but there is usually 5 or 6 litres of fuel that the car can never get out of the fuel tank.

      Or, the drain was not done fully and it still had some wrong fuel in it.

      I would suggest you contact the company that drained it, most of them are very good about it and will come out to see what went wrong and put it right

      Take care

  • Graham Lindsay

    Hi there, my brother accidentally put £6.00 petrol in his new skoda superb 1.6 diesel,
    About 2 months ago, however he topped tank with diesel and as the car is a taxi it has been filled nearly every 2 – 3 days , the last 2 days however the engine management light has come on and he arranged for it to go to skoda dealer, the fault code came up with clutch pressure limit reached, (car in limp mode ) skoda did not give a reason for this code but reset and drove ok, it came on again and again went into limp mode, went back to skoda. They said they removed tank and have removed fuel to be sent to away for testing as suspected fuel contamination, could this possibly show up and be the cause after all this time, the dealer said that if they find that fuel contamination is the problem it will not be covered under warranty and will need tank, fuel lines, common rail , and pump all replaced, however if they do not find this to be the problem they will replace all under warranty.

    Many thanks. Graham

    • TheFuelMan Post author

      Hi Graham,

      Clutches and fuel systems are not related, I sincerely hope the dealer is not using a slight misfuelling as an excuse to leave your brother high and dry without a warranty claim, please let me know how it turnd out

      Ta

  • Dan

    Hi, I put 10 euro (around 5-6 litres) of petrol on top of 20 euro diesel into my Nissan Note Diesel engine and drove under a mile, I’d guess at 600 metres , is it likely that there is any damage done? Do I need to drain or could I just fill it up with diesel? Thanks

    • TheFuelMan Post author

      Hi, not likely any damage has been done but 20 euro is a lot of diesel for a small tank like the nissan note, a fuel drain is the answer to your question.

  • Allan t

    i filled a 2011 sprinter with petrol, but meter started the engine. Our own guys drained the tank and filled it up with diesel.
    It worked fine that day but after a bit of chugging and a loss of power it packed in.
    Before mentioning the petrol, both the breakdown van and the guy from the fleet company reckoned it was a fuel injector problem and that it was pretty common. Would the petrol (if there was any remaining it would have been a litre or 2 at most) have caused this issue?
    My concern is that it was deemed as a warranty repair until my manager mentioned the P word and I’m probably going to have to foot the bill

    • TheFuelMan Post author

      Hi Allan, sorry to hear you might be on the hook for this, I would be surprised if you had damaged the injectors, sounds like it

      Sounds like the mechanics have either 1) not got all the petrol out, vans can be hard to drain because the tanks are shallow and wide – the van has to be tilted towards the filler neck for the drain to revover all the mixed fuel, or 2) they did not flush out the filter and lines properly.

      I would recommend a fuel drain from a professional fuel draining company, most likely that will fix it

      Good luck!

  • Andrew

    Hi,
    I have a 1.6l fiesta ztec s 2006 plate, I put in 5litres of petrol into the car which had 1/4 of a tank of diesel in it. I then realised the mistake and topped it up with 40 litres of diesel, will I need to have the tank drained?

    cheers, andy

  • Stephen

    Hi my father in law put 1/3 petrol into our 98 Diesel Mercedes Campervan yesterday. Having realised his mistake he then went and topped it up fully with diesel and drove it for 30K (Oh dont get me started)….. He reckons it will be fine. But today we could only start it with a struggle. It has always started without having to give the accelerator any power and always first time. We are seriously worried as are due to bring our 2 little girls to cornwall from Ireland on the ferry in 2 days and the thought of being stranded somewhere not sitting well with us. We tried it again a few hours later and was even worse. Help? Do you think a fuel drain will see us right? Thanks.

    • TheFuelMan Post author

      Hi,

      Not much I can do about strained in law relationships but once you have had a fuel drain done it will be fine, ray kavanagh covers dublin and if he cant help he will know someone who can, dont worry about long term damage to the van old diesel mercedes engines are as tough as they come it takes more than a bit of petrol to hurt one. hope that helps, call me if you have any questions, and enjoy your trip,

  • Dan Long

    Hi, I purchased a Mini Cooper S 2007 petrol car and the garage I purchased it from filled the car with diesel from a jerry can in error to take me for a test drive. The car was fine and then after I purchased it and went to drive away it kept stalling, it was quickly identified that the wrong fuel had been used.

    They took it to their garage and drained the tank. I then immediately went to the garage and filled the tank up and drove it for two days with no problem. But now the engine management light has come on and the manual suggest emission problems take to garage as soon as possible.

    I have refuelled the tank and it has been suggested from people I have spoke with that I drive it and refuel again once I have used a quarter of a tank and then do this again to dilute all the diesel and then run the tank right down and then put a full tank in.

    Do you think this is the way forward or do you suggest something else.

    I look forward to your opinion.

    • TheFuelMan Post author

      Hi Dan, take it back to the garage and insist on a full oil change, what happens is the diesel doesnt burn fully in a petrol engine and ends up filling the pistons with unburnt liquid diesel which pushes past the piston rings and ends up in the sump, this dilutes the engine oil with diesel and raises the oil level, it also can clog exhuast sensors and engine management sensors, hope that helps

  • charlie

    hi
    yesterday I put £40 petrol in my 3.6 td8 range rover, I then drove for around 10miles with problem but then it died!!. I was then towed to a garage where I then added £80 diesel. when the car started it was a little smoky but drove ok. Can I keep topping it up with diesel to dilute the petrol?
    Thank You

  • Andy Mason

    Hi, I’ve just put 5L of unleaded petrol in my Diesel 2003 Mercedes Vito 109 CDI Compact Van.
    Luckily I noticed and stopped filling at 5 Litres…I then topped up with 61 Litres of diesel before starting van and it seems to be running absolutely fine (no pinking/spluttering etc) and drove 10 miles home.
    Then just spent 2 hours reading various forums and it sounds like it could cause damage to high pressure fuel pump etc.
    Van is 9 years old with 73k+ on clock.
    Will I need to drain the tank for such a low ratio mix…..I’m not sure on tank size but with what was left in tank there must be close to 70+ litres of diesel to the 5 litres of unleaded?

    Thanks in advance,
    Andy

  • Antony Hunt

    Hi, i wondered if it is possible to tell if a diesel van has been accidentally filled with petrol? I know it sounds daft, but over here in Spain we still have petrol attendents and the other day i filled up and drove back home no problem. But when i came to start the van the next day it started but ran very roughly, i have done all the obvious checks and am now beginning to wonder if it has been misfuelled? Any advice gladly received! You don’t fancy a trip to Spain do you :o)

    • TheFuelMan Post author

      Hi, and yes I do fancy a trip to Spain!, It sounds like it could well have been a misfuel, an easy way to check is just sniff the tank, but right before you do that sniff a diesel tank from another vehicle that you know hasen’t been misfueld, then sniff the tank of the van in question, the Diesel should smell oily and sour, if it smells anything other than oily and sour it has been misfuelled – it wont smell “a bit like petrol” or “funny” – if it is 100% diesel. I dont know any fuel drainers in spain but if you tell me the type of van it is I could talk you thru it,

  • Kerry Myles

    Hi,
    I have a BMW 1 Series 118d, 06 plate and I put 7 litres of petrol in my tank before I realised my mistake. The tank was nearly empty and the AA stated they would be several hours. I couldn’t wait on the forecourt as I needed to pick up the children. I topped the tank up with 41 litres of diesel and drove away, approx 60 miles with no obvious signs of a problem. Tried the car today and it started fine, but I am very worried due to all the different posts on the Internet that there might be catastrophic damage occurring under the bonnet.
    Any suggestions on the next step would be greatly appreciated.
    Many Thanks
    Kerry

  • Quinn

    Hi. ok this is all my own fault I drive a renault cleo petrol & because I needed to save on fuel one day I put 6 letres of clean cooking oil in and topped my tank upto brim with petrol. It drove fine for weeks till my tank got down to quarter then engine light came on and it ran like a bag of sh-t for a day then died. I filled my tank up with petrol full. and it did start and it drives but with no power can’t get up hills without a run at them nearly crawls. how long before my oil makes its way out of my car and starts to run normal again. would a long ride down the motoway flush it through? please help Quinn

    • TheFuelMan Post author

      Hiya, sorry to hear your predicament.

      I would suggest you get a fuel drain, or if you want to save a few quid study up and do it yourself, clean cooking oil is not a good thing to have in a petrol engine and you should get it all out to save yourself the greif

  • Jon

    I own a BMW diesel engined Omega, the straight six diesel 1997 model.
    I don’t drive the car that often as I work away from home. Just recently there was a bit of a problem starting and in one case it died while running. I was also told there were leaks from the leak off pipes and then #4 injector started leaking. All this happened while I was away from home. I had the local garage look at this and also to try and source the problem of feeling underpowered, possible dirty fuel or poor quality ‘supermarket’ fuel causing dirt on the pump throttle potentiometer and part blocking injectors leading to high back pressure and leak of pipe failures.
    However on checking the fuel filter, they found it full of petrol! Someone must have mis-fuelled it. All this time it was still running, now I have no idea how long the petrol was in the system so have no way of knowing if the fuel lines have been damaged. All the leak off pipes have been replaced and the tank filled with petrol. I think they got 60 litres in so the tank probably had only 10 or so litres left. As far as I am aware the car is running fine now with no starting or running problems, I am still away at work so cannot verify this myself. Do you think I would still need to carry out a fuel drain or with this older engine, would it now be OK? My concern is the lack or possible lack of lubrication in the HP pump and this failing in the coming months. Can you advise please?

    Cheers

    Jon

    • TheFuelMan Post author

      Hi Jon,

      I think the worst of it has already been done, just run the tank down and fill it to the top with diesel and it should be fine, if the pump was going to suffer a fuel drain now would not make much of a difference, but from what you are saying I think it will be ok, – I would suggest a new filter once you have gotten thru half of the clean tank of diesel

  • Josie

    Hi,
    i put diesel into my petrol Beauford (kit car) I have drained it, cleaned injectors etc. It ran ok, a bit spluttery for a couple of weeks but it just stopped the other day. Went through the system again. i can get the fuel to the injectors but will not start. i have cleaned the injectors, checked relay, distributor, etc. everything seems ok but i am stomped??? Any ideas??

  • glasgow skip hire

    Hello, I was wondering if you could help me, last week I collected a skip from a garage that had been shut down and it had 3 drums or mixed fuel in it- (petrol and diesel), a friend suggested I use it in a space heater, is it safe?

    • TheFuelMan Post author

      Safe? – not very, space heaters are designed to work with kerosene which is much safer than petrol and not explosive, although I have heard of mixed fuel being used in space heaters I would not do it myself or recommend it,

  • Justyn Bryne

    Hi, I put £10 of unleaded into a VW 1.9 TDI PD last Sunday. I think there was about £10-£20 diesel already in it (a quarter tank).

    I did not realise at the time and drove about 30 miles although I did notice the car twice cut out on the journey when slowing down and changing down to 4th gear. Once I took my foot off the clutch the engine “bump started” again. After several hours at our destination I found the car took three long attempts to start and I realised my mistake. I went straight to the nearest garage and added £40 of diesel as that’s all the cash I had on me and it more or less filled the tank.

    Since then the car has started fine from cold but is hard to start when warm or hot. Once running it runs absolutely fine. I have been trying to use up the tank of fuel this week so I can add more diesel so it has almost pure diesel in it. I never though about draining the tank until today and I did not know there were specialist companies who do this.

    Do you think the petrol/diesel mix could be vapourising when the engine is warm hence causing the hard starting problem or have I ruined the pump?

    Should I go for a drain at this late stage or let the fuel get as low as possible before filling with diesel again?

    Many thanks in advance for any advice.

    • TheFuelMan Post author

      Hi, I doubt the pump is ruined, most likely the mixed fuel is confusing the sensors in the exhaust system, being a Volkswagen I would go for a fuel drain, the volkswagon diesel tanks dont take well to petrol and it corrodes the tank wall – leeching rubber into the fuel system, best to drain it

  • ade

    had engine failure come up on dash pulled over turned of engine .car restarted nothing on dash so carried on to home seemed fine . never used car next day went to restart lights on dash everywhere and wont start .they say petrol in fuel system have not filled up for over a week driven about 350 miles since so if did use wrong fuel wiil it have caused magor damage .there was just under 3/4 tank of diesel in it when refueled last week so 1/4 of petrol if this mistake was made .

  • john

    arrrr just put £30 of petrol in my 307 peugeot 1.6d then topped up with £40 diesel with say £5 of diesel in the tank already ive drove 2 miles with no problems think i should drain it ? or will it burn through ?

    • TheFuelMan Post author

      drain it!, you will be very lucky if it starts again from cold… as ive said a few times on here it not the end of the world but it definitely needs drained, the 307 isnt a big tank either so 30 quid of petrol is a lot of fuel for that size of tank

    • john

      HI i have a 57 plate A3 1.9 dti i put 35 pounds on unlead in on friday started, drove it till it died then i realised what i done, so got it recoveryed to a garage for drain it clean out the tank and line, replace the fuel filter. half fill the tank with diesel for me. I pick the car up sat started up fine for me drove it away i did approx 10miles in it before it died now the car would start, got it back up the garage (recoveryed again) it then start at the garage they drove it around with me in it and its died again now does not start any ideas?

      thanks
      john

      • TheFuelMan Post author

        Hi John, yep, I do have an idea on this, it sounds like it was not drained properly, the A3 has a twin fuel tank set up and its not unheard of for a garage to only drain one half of the system, I think you still have petrol in it i’m afraid so you best call a specialist fuel draining company

  • Kieran

    Hello,

    I have a 2004 Alfa 156 1.9 common rail turbo diesel and filled up just under 12 litres of petrol on an empty tank (the light had just come one). I filled up the remainder of the tank with 46 litres of diesel. I drove a mile & the car is parked up now.

    The car ran fine for the short journey home but that was probably running from what was in the pipes. Is my engine going to die a horrible death? What should I do?

    Thanks

    • TheFuelMan Post author

      Hi, sorry to hear about the Alfa, no, your engine wont die a horrible death,But I would definitely recommend a fuel drain for first thing tommorow, don’t worry if your car doesnt want to start – thats normal after a misfuelling once the engine goes cold it doesn’t like to start again with mixed fuel, it might sound bad but really once the fuel is sorted out it will be fine, we do about 6 cars a day in the same state as yours and 1 for 1 they are fine, call us if you need us, or just google “fuel draining” and someone could be with you within an hour or so and have it fixed in 30 minutes

      Good luck!

  • ashneel sharma

    i put little less then 2 litres of petrol in my toyota townace 2 litre diezel engine van. but it already had half tank diezel before filling that petrol. then i topped up with another 6 litres on diezel. i drove for 10 mins only, pliz advice do i have a situation.

    • TheFuelMan Post author

      Hi, No I dont think you will have an issue, to be on the safe side run the fuel as low as you dare before filling up with a full tank of diesel

  • 306derv

    i put around 13.5 litres into my diesel 306 which already had below quater of a tank but not empty of diesel and i then topped up with another 30 litres of diesel on top, i then drove the car ans me and my parnter drove home bout 16 miles and then the car would not start im thinking this is because we park on a hill parking upwards so it will have got a gob full of petrol. We have drained this out ourselves of around 20 litres from a full tank to below half but above quater and she starts so were just leaving the car running out till shes dry then going to fill her up wil diesel and drive her like normal. Will the engine be oki its on a P reg 1997 on a 1.9tdi? were going to replace the fuel filter for own piece of mind so do you think the car will be oki? thanks

    • TheFuelMan Post author

      Hi, the car should be ok, you should fill it up to the top with clean diesel the pug 1.9 engine is fairly good at dealing with wrong fuel from time to time, a new filter wont do any harm and they are simple to change on those cars.

      Hope it woroks out

  • Katie

    Hello,
    I bought a Renault Scenic (diesel) last week and on my 3rd day, mis-fueled and put 10 litres of petrol in it (There was already about 10 litres of diesel in there too)
    I drove the car on two short journeys, about a mile each way and it was chugging and spitting out strong fumes, but managed to get it home before calling out my breakdown service. They towed me to a local garage who performed a fuel drain for £100 and told me it would be fine. I filled the tank about 3/4 full of diesel.
    Since then, the engine temperature rises quickly when I drive, and there are still strong fumes coming out. Is this normal?

    • TheFuelMan Post author

      Hi Katie,

      Sorry to have to say this but no – it is not normal and from what you are saying it I would think there is another problem with the car, how old is it? and is it using water or oil?

      let me know how it goes

      The Fuelman

  • Brand New Car

    What if it’s the dealer who put about a quarter of a tank of diesel in your brand new VW Golf petrol engined car ready for when you picked it up for the first time! The car has now been driven 22 miles and been collected by the dealer’s recovery service. I wonder what work they’ll recommend needs doing and what the effect onmy warranty will be??

    • TheFuelMan Post author

      If it was me I would hand the car back and insist on a another one, you dont want to be driving a brand new car and never knowing if it will have a problem later on.

      Diesel in a petrol car is not a good thing, the diesel does not burn in the piston and slides through the piston rings eventually filling the oil sump up with diesel, which a) doesnt lubricate the engine and b) can cause major damage thru too much oil

      Ta

  • Ronni Sclater

    Hi,

    I bought my Audi A3 2.0 TDi only 3 months ago… last week it lost power and the coil light starting flashing. I was in the red on my way to the petrol station when this happened and noticed that I was toiling to get my speed up above 40mph (on a dual carriageway… not good!). I managed to get it to the petrol station, put a full tank of DIESEL in the car and when travelling home the car engine died… I left it for a while then started it again when another warning light came on the dash which was the emission control light, I managed to get a short distance along the road when the engine shut down on me again… got it started again, enough to get my car back home.

    The car is covered by a 12month Car Care warranty and was advised by the dealership that sold me the car to take it to Audi to get a diagnostic check done on the car. I got it recovered to an Audi dealership that ran a diagnostic check on the car and have come back and said that there is SWARF? (Not sure if that’s how you spell it..) in the fuel injectors, leads, high pressure pump etc etc and the cost to replace a full front to back fuel system in the car will be in the region of £6k which will not be covered by warranty as the fault they are diagnosing is caused due to contaminated/miss fuelling.

    I was asked where I fuelled at as not all diesel is to EM standards… since owning the car, I have always fuelled the car with DIESEL at reputable outlets i.e. supermarkets… I think thereby it is safe to say that these suppliers could not afford to sell contaminated/sub standard fuel, or we’d be hearing lot more cases like mine being raised!

    When asking how this could not have come to light before now, I was advised that this could take some time for the tiny particles to work their way through the fuel system but I have to say that I’m a bit shocked to hear that if this is the case I’m not covered for someone else’s wrong-doing, if that’s even the case!

    The dealership that sold me the car are recommending that I get the car recovered (again – at a cost that I’ll need to pick up..) to another Audi specialist dealership for them to check over the car as his own option from what symptoms I have told him was that the car could be ‘flushed’ with possibly some parts needing replaced to sort this problem out which would cost a lot less than the £6k I’m currently being quoted from the Audi dealership… but I’m not convinced, surely some evidence of miss-fuelling would have come to light before now? I feel that the cause is something as simple as something, possibly a bit of debris that was in the tank that managed to get through the fuel filter which is blocking my injector/s that is the problem here… or from what I’ve told you, do you think that maybe someone in the past has miss-fuelled and I’m the one having to pay the price of their actions?…

    I have spoken to another ‘independent’ Audi specialist who said the car was misfiring hence the coil light coming on and that the engine most likely went into ‘limp’ mode which is a fail safe option for the engine management system to limit any further damage…

    I really don’t know where I stand in this dispute… any guidance on what you think the cause could be/what I should do would be greatly appreciated!

    Thanks!

    • TheFuelMan Post author

      Hi,

      Sorry to hear about this,

      the first thing I would do is check if there is any petrol in it now, go one further and put a few drops of fuel on a bit of metal and try and set fire to it with a lighter,

      if it burns readily, or smells of petrol then that would suggest a fuel drain could fix it, call us if your in the south east, If it isnt fuel related then I would take it to another audi dealer for a second opinion BUT DO NOT TELL THEM WHAT HAS BEEN DIAGNOSED SO FAR – let them do an open minded diagnostic check and see what comes up

      Hope that helps

  • Angie Stevens

    Thank you for your reply.
    It’s really reassuring to know this. I’m really very grateful for your advice.
    I’ll keep running it and will hope that the trail of angry motorists behind me understand……
    I wonder if it’s in limp mode? Engine is still knocking a bit in first gear when revved and engine feels like it has no torque.
    Good to know there are people like you around.

  • Angie Stevens

    Hi, I misfueled a week ago and put in £40’s worth of petrol into my diesel 1.8 (had about 80 miles left) I drove it for a week (very short journeys) It went ca-put a week later and Ive just had it drained.
    I’ve just filled the tank to bursting and Ive driven it for 25 miles. It’s slowly improving but in first gear there is no pull at all and lots of clouds of smoke.
    I hoping I havent damaged my car beyond repair. At the moment any hills seem like a no no, I could walk faster.

    • TheFuelMan Post author

      Hi,

      could be a few things from what youve said, but if it seems to be getting better just keep topping it up, if its still not quite right after 3/400 miles put it into a garage, could be a sensor or needs a new filter,

      Hope that helps

  • Richard

    HI mis-fueled, my skoda today £55 of petrol in there was about £10 of diesel left in tank. Have had it drained and have put £50 diesel back in car ,its not running right losing power at 3000 revs and not starting properly any ideas
    Many Thanks

    • TheFuelMan Post author

      Hi Richard, my first suggestion would be to fill the tank to the top, – 50 quid isn’t even a half full tank on most cars, it sounds like you have a bit of petrol left in it and the more you dilute it the better, it should be fine after a top up

  • Mike

    I have 2011 Jetta TDI that had misfuel about 50/50 but only drove a few hunderd yards and shut it off and towed to dealer. The dealer claims they found metal particles in the filter therefore the entire fuel system has to be replaced ($10K). I have also see on many blogs that if you see metal particles that HPFP needs to be replaced. Have you seen this occurence in your experince and should I be concerned? Do you think if I do fuel drain and replace filter it will be OK?

    • TheFuelMan Post author

      Hi Mike, your dealer is talking…… shite, there is no way metal would get into the filter – and if it did the dealer would not have a clue how to find it, (unless they employ a forensic matallurgist with a fully equipped lab), to answer your question you should be concerned – your dealership are opportunistic lying scum, but your car should be ok, drain it and replace the filter and all will be fine, come back and let me know how it goes!

  • Joe burns

    I mis fueled and ran my diesel car for 55 miles parked up came back two hours later and it wouldn’t start, I tried again and again not realisng I had put the wrong fuel in. It started again and I drove a further two miles parked up and came back an hour late, car wouldnt start. Then I realized what I had done. Called the aa out, they towed me back home to the dealers ( Renault) they now said that they have to drop the tank to clean it out and it will cost me £400. The car is only two weeks old and I only done 500 miles.
    Question is how could the car run for all that time, and why do they have to take the tank out,I feel they are just fleecing me for money?

    • TheFuelMan Post author

      Sorry to hear that Joe,

      You’re instinct’s are correct – your Renault dealership are fleecing you, but in fairness £400 quid is a very light sting from a dealer!.

      To answer your question, I doubt they will take the tank out, it will most likely just be drained, you can check this yourself because there are straps that hold the fuel tank in underneath the car – have a look at the screws or bolts on it – since the car is only a few weeks old you will be able to see if they have been undone and refastened.

      Hope that Helps

  • Nicola Pollard

    Hi.

    Please help. I put around £50 of petrol (had around £10 of diesel already in) into my diesel VW Jetta 2.0 tdi on 14th Dec. I did not start the ignition and was towed home. The very next day the car was towed to my local garage and they drained, flushed the system, fitted a new filter and added some diesel for me. I then filled up the car with the correct fuel after picking it up and gave it at least an hours run. One week later I have used the fuel and am onto my next tank full of diesel. Problem: since I picked up my car it runs fine, starts first time in the cold, however if it has warmed up it takes a few cranks to actually start again. It does but I’m worried I could be doing damage to it. Can you think of what could be causing this as my local garage thinks it’s a coincidence (I don’t as it was running absolutely spot on before I was a bit of an idiot)?

    • TheFuelMan Post author

      Hi Nicola,

      it sounds like there might have been a little bit of petrol left in the system, it can cause issues with the EGR valve which is in the exhaust, the EGR valve sends constant signals to the engine management unit to regulate fuel flow, petrol can sometimes but not often mess these up – theres every chance it will clear itself soon, before you spend any money at a garage I would reccomend running the car on low as fuel as you dare, and then filling it up to the top with diesel, that should help flush the last of the petrol out, do that a couple of times then put in some injector cleaner, this is added to the fuel tank and helpt clear residue,

      Let me know how it goes

    • TheFuelMan Post author

      Hi Nicola,

      it sounds like there might have been a little bit of petrol left in the system, it can cause issues with the EGR valve which is in the exhaust, the EGR valve sends constant signals to the engine management unit to regulate fuel flow, petrol can sometimes but not often mess these up – theres every chance it will clear itself soon, before you spend any money at a garage I would recommend running the car on low as fuel as you dare, and then filling it up to the top with diesel, that should help flush the last of the petrol out, do that a couple of times then put in some injector cleaner, this is added to the fuel tank and helpt clear residue,

      Let me know how it goes

  • Matthew Dixon

    Hi
    My girlfriend put 5litres of petrol in to my diesel car. This was said to be okay so we topped up the tank and it went fine, how ever the engine management light came on.

    Then I stupidly a few weeks later done the same thing, but I got the car drained

    If the management light has stayed on does it mean something is damaged. I took it to the garage and they have replaced my additive tank and now saying I may need a new DPF filter

    Any advice

    • TheFuelMan Post author

      Hi, you should take it to a garage and have the fault code read and reset, if the management light stays off your problem is solved, I havent heard of dpf’s getting damaged by a misfuel but there are sensors in the exhuast that can get fouled by petrol deposits, it can be cleaned or replaced and shouldnt cost a fortune.
      hope that helps

  • Shane Davis

    I misfuelled for the second time in 9 months in the same w reg 2.2 DTi Frontera… I didn’t realise I had put 17l into an empty tank… Car stalled 0.9 miles from the petrol station, so I called Fuel Drain. (Again.) 2 vans, 2 men 2 1/2 hours later, still no starty! No charge, Autoshift carry to the garage down the road from me, and still no starty. They are starting to query fuel pump. could this be correct? I’m crapping it as the costs for that are staggering… There is diesel coming from injector pies 1 and 4, but only a weak flow from 2 and 3…
    Your thoughts please…
    Shane

    • TheFuelMan Post author

      Hi Shane,

      Sorry to hear about the 2 misfuellings,

      Ok, so there are 2 fuel pumps in question,
      the first is the electric pump in the tank which “sends” the fuel to the engine, and then there is the high pressure diesel pump, – (expensive one)
      the in tank pump would unlikely be damaged by a misfuel and only costs a few hundred to replace at the most, the high pressure pump is the worst case scenario, Not having done the fuel drain there are a couple of things i would check, did they try bleeding the air from the return end of the fuel line? and is the tank 100% clear of petrol?, before you go spending big money I would suggest the crude but effect tow start this would involve a willing friend with a powerful van or car, simply force starting the car, (i wouldn’t normally suggest it but since its a ten year old car it won’t do it any harm) , as for the weak injector pressures I wouldnt read too far into it unless it has been a proper pump out bench test – there would be no reason for 2 injectors to be lower pressure that the other 2, its a common rail engine and therefore all the injectors work off of 1 common rail – if your stuck give us a call,