Will diesel cause the AOS/MAF to fail?

[Qmulus]

Originally Posted by Coaster

Found out that the local station swapped diesel and premium this past weekend

I got the gas Sunday morning and when I started the car Sunday afternoon it puffed big blue smoke clouds. Shop is cleaning the fuel system. I find it hard to believe my one year old AOS failed exactly after getting diesel in the tank. I'm in discussions with the station insurance and want to make sure I submit a complete and fair claim.

Could the diesel have cause the AOS and MAF to fail?

I have seen a few cars where that happened. The blue smoke is from the diesel in the gas. Once the fuel system is thoroughly flushed, and probably a change of plugs you should be fine. It likely will smoke a lot until all the diesel is burned out of the system. That can damage the O2 sensors and cats, but you are probably OK. I doubt that there is anything wrong with the AOS or MAF.

FWIW, a few years ago a local Audi dealer had a girl bring in an '02 S4 that started missing badly, then blew large clouds of blue smoke and stopped shortly after filling up with "gas". The dealer techs diagnosed it as a blown engine and quoted some outrageous sum for a new engine. She ended up taking it to another slightly shady independent shop that replaced the engine with a used one for half the price, which was still a huge profit. Once it was started, it too blew blue smoke and stopped. That is when they figured out that the tank was full of diesel fuel. They flushed the system and all was well, after a LOT of smoke. They didn't tell the owner the real problem, and kept the original engine that had no real problem...

[flaps10]

Which is why no one touches my car with a wrench but me.

Originally Posted by Qmulus

I have seen a few cars where that happened. The blue smoke is from the diesel in the gas. Once the fuel system is thoroughly flushed, and probably a change of plugs you should be fine. It likely will smoke a lot until all the diesel is burned out of the system. That can damage the O2 sensors and cats, but you are probably OK. I doubt that there is anything wrong with the AOS or MAF.

FWIW, a few years ago a local Audi dealer had a girl bring in an '02 S4 that started missing badly, then blew large clouds of blue smoke and stopped shortly after filling up with "gas". The dealer techs diagnosed it as a blown engine and quoted some outrageous sum for a new engine. She ended up taking it to another slightly shady independent shop that replaced the engine with a used one for half the price, which was still a huge profit. Once it was started, it too blew blue smoke and stopped. That is when they figured out that the tank was full of diesel fuel. They flushed the system and all was well, after a LOT of smoke. They didn't tell the owner the real problem, and kept the original engine that had no real problem...