Serpentine belt rattling at AC compressor pulley, loses drive periodically on 1996 Buick Century

These may be separate problems but when I start the car it immediately begins making a rattling noise like a nickel vibrating in a tin can. I tracked it down to the pulley in the serpentine belt for my AC compressor. The pulley seems to be spinning freely but the face of it rotates very slowly and there are metal shavings around the edges and under it. I honestly don't know if the face is supposed to be immobile or what but it spins. and it's grinding somewhere.

The other problem I have (related or not) is that the car has completely cut out on me twice. It suddenly feels like it's gotten knocked into neutral (power brakes out, steering suddenly heavy) but the engine won't rev and I have to let momentum get me off the road. Radio stays on the whole time though. Shutting the engine off and restarting has fixed the problem both times. Is this a belt problem or just a bad coincidence?

Asked by for the 1996 Buick Century

sounds like a problem i've had. mine was the idle pulley. makes the belt skip and if bad enough can lose power and die.