So much SMOKE!
 

Okay,

Another one for the audi geniuses here.

So, I purchased a 2001 A6 2.7T months ago and have been working on it WAAAYYY too much...I'm beginning to go insane.

I bought it with at least one bad turbo. After pulling the turbos I found that the driver side turbo's impeller shaft had completely snapped in half...welp, there's your problem!

Long story short, after having the engine in and out a few times and replacing both turbos with a set of used "good turbos." The passenger exhaust started pouring out smoke and sputtering oil as well. No smoke on driver side. (exhaust disconnected just behind DPs) Car was running well though.



After assuming that I that I purchased one bad turbo and one good one, I purchased another used passenger side turbo and installed it. After starting....no smoke then after warming up and some revving....smoke again!

So, some details about when it smokes. It appears to be mostly or all oil smoke (oil sputtering onto the floor).

If I just start it and let it idle, it doesn't seem to ever start to smoke, only when I rev it up to about 3 - 4k and hold it there.

I was thinking that the chances of purchasing another used "known good" turbo was slim, so I started to think maybe it wasn't the turbo, but coming from upstream in the head somewhere. I pulled all the passenger side spark plugs and did a compression test. All seems well, around 160 -165 psi on each and same with one cylinder that I testes on the driver side. Cylinder didn't seem to be sputtering out any oil when plugs removed and cranking.

And the oil level does not seem to be changing at all despite running while smoking for 45+ min.

Then I pulled the EGT sensor on the passenger side and started the car and ran it up until the smoke started. Couldn't really see any smoke coming out of the EGT hole.

I was hoping it might have been oil in the DP burning out of the cats. But the driver side is that side that had the worse turbo failure and worse oil hemorrhaging in the first place, so why would that side not be spewing smoke as well?

My last option is going to be pulling the DP off and running without it.

I guess the question I really have is...is there any source of oil that could be coming from the engine/head that would cause that kind of smoke? I wouldn't think valve stem seals or anything could cause that.

And if it was a head gasket issue, I think I would have poor performance, pressure in the coolant system, bad compression....

HELP

Turned out to be A LOT of oil in the catalytic converters...

Took...Forever...to burn out...

Before you replaced the turbos was your car boosting at all with one bad turbo? I have one bad turbo right now and the other appears to be okay, but my boost gauge is reading 0lbs of boost.

Not sure
 

I didn't really run the car long enough with one bad turbo to notice. It depends on how your turbo is broken though I suppose. Mine had a massive failure where the shaft in the turbo actually snapped in half and the exhaust side impeller fell off.

So, in that situation, the ecu would see a negative boost deviation to a point where it would probably cut boost down to 0 using the N75 valve controlling the wastegates.

If you only have say...bad seals in your turbo, I would expect it to still boost some.