Noisy Serpentine belt

[688i]

It did sound like a chirping bird when idling but went away when RPM was above 1500. Based on another post here and visual inspection of the tensioner pulley, shimmed this pulley with a washer custom fit to improve alignment, but this did not help and made a little worse. Tried spraying belt treatment on belt and it stopped the noise immediately and all day long. Problem is when you go to start car the next day the noise is really bad until you spray with belt treatment again. Any ideas on a more permanent fix? Belt does not have 10K miles on it and has been making noise since replacement.

[HotZ28]

What year is your PA and is it a base model, or an Ultra? What brand belt did you install 10K ago? You should never spray a serpentine belt with belt dressing, as you have just confirmed, it makes matters worse. I killed the “chirping bird” sound by installing Goodyear Gatorback belts. When you install a new Gatorback belt, use brake clean to clean the belt dressing ‘sticky goop’ off of all the pulley’s. In addition, be sure to check the condition of all idler & tensioner pulley’s while the belt is off.

[xs03mich]

Depends on how bad the chirpping is. I have done this procedure in the past and it has helped in getting rid of the chripping. Start the car up, take a piece of wax candle, I hold it with pliers, put the candle on the underside of the belt for 15 seconds or so as the car is running. Notice the little stuff the candle wax will pick off the belt. Next thing I do is the same thing with a piece of chalk. Most of the time with these little tricks I can get the belt to stop chirpping and save me from spending $$$ on a new belt. Just remember to use pliers to hold the items.

[logicchoice]

Since the noise goes away @ higher RPM's it sounds like a bad harmonic balancer.