squealing belt **video
 

I just started hearing this screetchy noise. I can't pin point where it's coming from. Any ideas?

986 belt - YouTube

Could be a belt tensioner. Remove the belt (mark its direction with a piece of chalk or something similar before removing, and make sure you install it with the same orientation). Rotate each tensioner by hand and see if you feel any resistance or hear a grinding noise; if yes, it needs replacement, which is fairly easy. Also, of course, check the belt itself.

I did remove the belt and spun it by hand. Spinning them by hand is smooth with no sound. I'm assuming since most/all of the whine occurs at 2000-3000 rpm and there is no stress on the bearing with the belt removed, I'm not able to replicate the problems by manually turning it.

I believe I've determined it's the bearing of the pulley on the right with the blueish color nut. Can someone provide me with a part number for the bearing used in this pulley?

Also, how do I remove this pulley, the screw that is used to hold this pulley in place is very long, also holding in the alternator. I can't remove this screw because it touches against the front firewall. Any ideas?

I've replaced the top pulley and the belt today the sound still persists.

As some of you who have had similar problems and tried to diagnose it, it is really hard to tell where the sound is coming from.

Would the bearing inside the alternator going bad cause a high pitch squeal?

In you don't have an automobile stethoscope, you can use a piece of rubber hose, put one end near your ear and carefully move the other end near each pulley.