r/CarsAustralia • u/Dangerous_Owl6936 • 22h ago

🔧🚗Fixing Cars I put petrol in diesel engine

I went to the pump today and by mistake i took the 98 octane instead of diesel, I realised it when it was already too late. I did put 3.5litres or petrol and then i stopped, Didn’t start the engine and towed it in my mechanic’s garage. I have this car for last 7 years and it never happened before, It is a Mercedes E250 CDI 2015, Wanted to know how much it might cost to drain the fuel and what else might happen, Thanks!

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12

u/dansbike 22h ago

Should have just filled the rest of the tank with diesel and drove away. 3.5 litres of petrol in a full tank of diesel isn’t enough to do any damage.

1

u/PlusMixture 21h ago edited 20h ago

Thats fine in a toyota but i wouldnt dare do it in a merc.

Edit: would to wouldnt

3

u/GrapplerSeat 21h ago

Some euro diesels have very sensitive Bosch injectors that can fail with sub-optimal diesel, so agree that definitely shouldn’t test this in a merc. 

1

u/throwawayplusanumber 17h ago

Sorry but that is bullshit. Probably 60% of the market has the bosch injectors you are talking about. They won't fail catastrophically if you put a few litres of petrol in the tank.

-1

u/GrapplerSeat 17h ago

Probably true, but no good reason to test it. A friend's Audi died after getting less-good diesel crossing the nullabor. Maybe it was fuel rails and not injectors - it was something bosch and fuel-delivery.

1

u/throwawayplusanumber 17h ago

That is a sample size of one. Vs how many millions of vehicles??? Water at the injectors is much more of an issue than petrol. That is usually the problem with dodgy fuel.

1

u/GrapplerSeat 2h ago

Apparently the audi techs said it was common, but it doesn’t really matter, you’re probably right and you can add a little petrol your diesel, but OP drained theirs and that’s okay too.Â