After having auxiliary belt tensioner replaced due to belt trying to jump off alternator pulley, I now have a diesel passat that sounds twice as noisy as it did previous to having the work done. After having the replacement, on a couple of occasions the alternator workshop light came on but since then no sign of the warning light. The noise appears to be coming from the alternator / steering pump area and the belt is still jumping on idle but not as much as previous. The guy who replaced the auxilliary belt tensioner advised that there is a damper fitted to the alternator but wasn't too sure how to check if the damper was working properly. '02 Passat Estate Diesel approx. 127000 miles any ideas please. Noise appears to sound as if there were two panels vibrating together as if an absorbent material had been removed and not replaced, a lot more noticeable on idle, any info. would be most grateful.