Weird noise-91 200TQ

[Michael Stricker <stricker@ll.mit.edu>]

Hi,

This query is regarding a strange noise I heard in a 1991 200 TQ (20 
Valve engine).  The car is stock and while it was warming up last night, 
I would rev the engine up to 1500 rpm and get off the gas.  The engine 
appeared to have a rapping sound eminating from the head.  This sound 
would persist for a few seconds then dissappear.  It is not the familiar 
sound of AUDI hydraulic lifters.  Does this engine have solid lifters?  
Could it be that they need to be adjusted?  The noise can not be heard, 
or at least I can't hear it, if the engine is not decelerating rapidly.

Any thoughts?  Does a chain connect the 2 camshafts?  Could it be that it 
has to be tensioned?

I was checking this car out.  It has 88K miles and has been dealer 
service since new.  The UFO brakes are still there but it had a recent 
brake job at 55K.  They appear to stop fine.  The drivers seat heater 
element is shot.  It's got the car phone and the body is in excellent 
condition.  The front end seems a bit loose but...I offered the dealer 
$12K pending a succesful resolution of the engine noise problem.  

Any thoughts or opinions are welcome.

TIA

Mike Stricker
1990 Quattro Coupe