1997 S70 serpentine belt squeak on cold starts and past 2500RPM when warmed up

[Zeiussy]

Hello everyone,

I have a base model 97 S70 that just got it's alternator and serpentine belt replaced, for a few days it ran fine but now the serpentine belt squeals during cold starts around the power steering area. This goes away when the car warms up but returns when I rev the engine slightly. The weird part is as the car gets used the "squeak range" goes up, 10mins in it will only squeak past 2500, then 10mins more around 3000. It never goes away though even after a long drive and is particularly annoying when passing other vehicles.

I've checked the belt itself which is brand new and it now has frays on the side away from the engine.

belt wear

It also looks like its not centered on the idler pulley. I also checked the power steering wheel itself and It looks ok to me.

20250621_171629.mp4

(7.27 MiB) Downloaded 26 times

Belt video while the engine is running

Im running a 6PK1743 belt with the newer routing as it doesn't seem like the belt is short enough for the older one instructed in viewtopic.php?t=60913. Im thinking of buying a shorter belt to see if that fixes it.

belt code

Any ideas? any help would be appreciated

[jreed]

It could be that one of the components is loose. Have you checked that the bolts holding the new alternator in place are tight?

[scot850]

Hopefully the top picture is of the original belt as it has pieces shredded on the side of it!

Check the tensioner is doing it's job. Mine failed shortly after doing this job after being tensioned out of the pressure point.

Neil.

[Vova585]

Based on the top photo one of the components has "play" which eats into the belt and causes its shredding. I would replace tensioner assembly and alternator pulley as my top suspects. Ac compressor bearing might have some wear as well. Power steering pump is less likely suspect.

[abscate]

Some of the -1998 belts have been reall tight on tolerance. Where does your tensioner sit relative to fully tight?