Join Date: Dec 2005
Nominated 2 Times in 20 Posts
TOTW/F/M Award(s): 18
Thanked 1,104 Times in 943 Posts
I strongly suspect that the pulley on this posters car has a clutch inside of it which has seized,this causes the belt tensioner to jump around on idle making a nasty vibration noise.To test,remove the belt and grab the alternator pulley,spin it with your hand clockwise and then abruptly hold it to stop it.You should feel the alternator internals run on for a fraction of a second with the pulley held still.If it doesn't then the pulley is fubar'd and it needs replacing asap as they can fail and cause allsorts of expensive damage,especially if the aux belt gets wrapped around the crank pulley and goes into the cambelt.
Currently in Lagdti's garage:
2004 Saab 9-5 HOT Aero and a 2001 Audi A3 1.8 Turbo