In the Vag-Com forum, I asked if anyone knew how to diagnose and test the turbo with a vag-com tool. Nobody replied yet, so I am asking here too along with other things.

1.My friend's '99 A4 1.8T has developed a clicking noise upon starting the car for the first time in a day. It sounds like the tappets or lifters clicking and usually goes away after warming up a little. This to me sounds like his oil pump is failing. I suggested he get an oil pressure test. If anybody has heard anything like this, please comment!

2a. Another noise has developed and I think it might be related, but I would like to be more sure. When you rev the engine after it has warmed up, there is a funny, fast clicking noise coming from the turbo side of the engine as the revs come down. It sounds almost like freewheel on a bicycle and only makes the noise as the revs are coming down. Could this be related to the tappet noise coming from the engine (i.e. could there be a lack of oil to both the tappets and turbo, thus causing this noise?)

2b. Could this noise be due to the DV valve being stuck not allowing the air to be diverted out of the turbo system and thus causing excess pressure to back up on the turbo???

Any comments are appreciated!
-Brad [img]/ubbthreads/images/graemlins/beerchug.gif[/img]