I recently purchased a used 2001 Audi A4 1.8T. After about 50 miles, i could hear the turbo rubbing on the housing and learned about the sludge issue in the A4's.

I used a quarter can of sea foam in the crankcase and idled the car for a while, it didn't smoke from the sea foam. The next morning the car ran fine for over a half an hour, then it started smoking out of the exhaust. I shut it down and had it towed home, discovered there was oil leaking out of the exhaust part of the turbo and the exhaust pipe.

I replaced the turbo, found that the factory turbo was shot, all of the turbines were worn and turbine on the exhaust side and shaft were loose.

After I replaced the turbo the car ran fine for a few minutes. Then another few minutes, i ran it off and on to make sure all oil and coolant levels were OK.

After about 10 minuted of running it smoked again. Smoke out the exhaust and the turbo was smoking and oily smelling.

Now what? Do i go for another turbo or am I missing a larger issue? I thought it was originally a turbo issue since the factory one I took off was toast. I haven't taken it apart again to check out the new one just in case there may be something else I can do. I purchased the replacement turbo from a turbo shop, aftermarket replacement.

Any help is greatly appreciated, Thanks.