Noize

[quk@sievers.com (Phil Payne)]

In message <961117151616_2014158515@emout18.mail.aol.com> Polidori1@aol.com writes:

> Here is another odd sound that begs for a diagnosis:
> 
> '87 4Q, 145K: "Grinding" sort of noise that is rhythmic with the rolling of
> the car.  Seems to come from beneath the car, just under the e-brake.

Check for prop-shaft/exhaust interference.
 
Under some circumstances, differential cooling of the sides of the exhaust 
cause one side to expand more than the other - effectively "bending" the 
exhaust towards the prop-shaft.  It happens if you drive over a succession of 
small puddles after driving quickly - it can also happen if something blocks 
airflow along one side of the exhaust.  When you crawl under the car, 
everything is in the right place, because the temperature differential has been 
removed.  Use mirrors and bright lights - takes some spotting.
 
--
 Phil Payne
 phil@sievers.com
 Committee Member, UK Audi [ur-]quattro Owners Club