I had a noise like that in an older Audi 2.8 engine. Loud in the winter until the engine warmed-up, but almost no noise in the summer. It was still under warranty, but Audi said it was "normal" on that 2.8 engine. It got slowly worse, and of course by that time the 36mo/50,000 ran out. I dumped the car in a trade-in during the summer. I never found out for sure, but I think it was a bad wrist-pin/piston combo.<p>Get your Audi dealer to fix it. It was not there when you got the car, and it's NOT normal.

If I let my car idle more than 30 seconds or so before turning it off the night before, I notice a very pronounced valve clatter (sounds like a deisel) for the first 2-3 seconds after I start the car in the morning. Also, this is only since since I switched to 10W30 (from 15W40). I never noticed any valvetrain noise with the 15W-40 (back when I was using conventional oil).<p>It is for this reason I decided against a turbo timer. I figuresd that would just make things worse. Instead of a timer I just stay out of the boost and drive very easily for the last 2-3 minutes before I park the car.<p>Paul<br>'98.5 A4 1.8TQTipS in Pearl