Whirring Noise from accessories

[nhproxr]

'98 Yukon with vortec 350. Got a whirring noise coming from accessories. Can't quite pinpoint it think it is coming from alternator or maybe belt tensioner. Maybe also water pump. Any ideas how to pinpoit it?? Take belt off and check for play in pulley? Any of these items likely to be the first to go at 136,000 miles (I'm sure all of them are near the end of their life!!!).

[citydriver]

Check the rear bearing of the alternator, it's supposed to be sealed, if the plastic cover is gone and you can see the rollers and cage its usually the first sign of failure....at least that's what I've found in the past....Also check the belt itself, a worn belt will also make noise......just a thought

[Guest chevydeerhunter]

Ditto the alternator. It could also be brushes going bad.

[asepgrad98]

try the old long screwdriver on the accessories trick, put your ear against your hand with hand on handle.

[OLERED04]

 

The old listening stick that how I usually tell just be careful