I have a 2007 A4 2.0 Turbo, ~80k. I have an ongoing (2+ years) issue that my mechanic and the dealer have not solved.
Every once in a while (2-3 weeks, sometimes more frequent), upon acceleration (onto a freeway, up a hill, etc.), a large plume of white/blue smoke comes out the back, oil burning. This is a large James Bond type plume. I literally am worried about people not being able to see large. This occurs then next three or four accelerations, smaller plumes of smoke each time, and then the car runs and burns cleanly for the next several weeks.
I have had the turbo replaced.
I have had a series of purge valves replaced.
I have had the system flushed.
Each of these has delayed the onset of the next event for extra weeks.
I suspect I have some sort of an oil leak that is being recirculated into the engine as part of the turbo system.
Any advice would be appreciated. I am taking the car back in and want to be able to describe what needs to be done.


Thanks in advance

 

Look in intake connection to the throttle body from the intercooler for excess oil building up over time. Also check the PCV valve. A good way to check this is while the car is idling, release and slowly remove the oil filler cap from the valve cover. If you feel it being sucked back to the valve cover, you're PVC valve is bad. This can suck excessive oil vapor into the intake. It also generally trips the Check Engine Light and throws a "Lean" OBD error code.

 

We had the same problem with new PCV clacking sound (I think) then smoke with any pressure on the gas. Then on a back country road, in Sport mode, accelerated hard till it smoked, let off and it stopped. Repeated. By 3rd rep, less smoke By 4th or 5th rep, no smoke! Now I drive 70% on Sport mode, so as not to load it up as I expect it does in D or econo mode. (Note, we'd used B&G (I think) gunk remover oil additive that requires you to run it hard, then change the oil, with limited effect (twice). About a month later, repeated heavy accel to moderate speeds - did the trick. But, it'll smoke again after wife drives it for a while. Then I blow the cobs out of it (we used to do this with our 327 small blocks, right?), and it stops fogging mosquitos. Still uses oil more than I like, but at 127,000 mikes, what a fun car!

 

By the way, this car stopped a Chevy S-10 pickup that rear ended us at 30 mph when we slowed to avoid a dog on a windy NC back road. Audi drove away, trunk still worked, S-10 towed with blown air bag and radiator! Audi repaired in N IL, looks good and all three of us in good health - no I'll effects - but man did that headrest hit hard!