Wrong Fuel In HDI engine

Some people think that HDI engines are ruined by having wrong fuel in them.

This is not the case, an HDI engine is High pressure Direct Injection, aka common rail, or CDI.

these engines are not damaged by a small amount of wrong fuel over a short distance, the doomsayer that say petrol will destroy a HDI pump or ruin the injectors are over enthusiastic arm chair mechanics, the forums are full of them.

The theory is a diesel pump is lubricated by the diesel in it and when its loaded with petrol it “strips” the metal and the metal grinds into shavings and this gets pulled into the piezo injectors and this mangels the injectors 1 by 1 and the car comes to a grinding halt and costs thousands to fix, in the fuel draining business the technical term for this is “bollocks”

What actually happens is when you put in the wrong fuel in any quantity the car will stop running before it hurts itself, sort of like a failsafe, and if the car can run on the wrong fuel mix you have – then its not that wrong, in summary no diesel car will even turn over on the ammount of petrol required to ruin it – or for long enough.

Usualy it goes something like this, you fill up at night, and start driving home the car acts a bit rough as you pull into your house and in the morning it refuses to start, this can leave some people with the impression that the car has now been ruined and the wrong fuel cdi/hdi thingimajig all went wrong and now it needs major work…..

What actually happend was you filled up the wrong fuelbut the filter and fuel lines and pumps still had clean fuel in them, you got home but as you drove the petrol started to work its way into the engine – so it felt rough, but since the engine was already hot it somehow just manages to go, however when you tried to start it in the morning it doesnt start at all – its not ruined! its just cold and full of the wrong fuel, this is when you should call for a fuel drain, it takes 30 minutes and your car will be fine, you will have joined the ranks of 5 million other motorists who have misfuelled and it really isnt the end of the world.

The Fact is, if a car has been misfuelled, it can be fixed, we have done close to 8000 fuel drains and I can count on one hand the amount of cars we couldn’t fix, and I certainly wouldn’t charge for a car I cant fix, that said we have seen cars that have had 2 things at once go wrong with them and it was nothing to do with the wrong fuel, but that doesnt happen often at all.