idler pulley, tensioner, or both

[bryan95m3]

My 95 M3 just had all the belts replaced at its 180k checkup!!:) anyways it has now decided to kind of chip when the engine is cold, once it warms up it seems to go away, however ive been told that it was the idler pully and tensioner but is it just the idler pully??? what really need to be replaced??

[Andycapps]

Hey..i replaced my belts about 5k miles ago..and mine chirp when its cold and when i first start it up. It really could be either of the two.

[fun2drive]

Tensioner pulley is worn out. It will squeal when cold and gradually go away when warm. I bet if you had need to put the AC on it would squeal as well when cold or even better turn you lights on to draw a good load on the alternator and it will most likely squeal. I replaced my tensioner when mine did that and problem gone...

[lesl2]

Take the belts off and leave it overnight. In the morning, turn all the pulleys to determine which one is chirping.

[CJH]

Do them all, not worth the effort to do one at a time. If one is gone, the other is likely not far behind it. These cars are getting old, ball bearings have a finite life.