Rattling coming from S/C.

[frownonfun]

So I've got this rattling type of noise coming from, I think, my blower. Have I ruined the bearings in it? What's the deal? Why is it making this noise? It isn't constant but it is there from time to time. Also the kit needs an oil change but it isn't THAT long overdue and I rarely drive my car these days anyway.

Then again I don't know if it's the way the belt is rubbing and it just needs changed. It's hard to tell because it is really intermittent. Not sure what the life expectancy is on the belt. Guess I could just replace it and see if the noise goes away.

Anyway don't know much about this stuff so any help is appreciated.