Idle Rattle From Pulleys?

[SC_Z]

Recently Ive been having an annoying problem with what seems to be one of my pulleys rattling, it sounds like dry bearings. It sounds pretty bad at idle but you can't really hear it when I go down the road because of the LM II exhaust. I changed the idler tension pulley but that changed nothing. Looking under the car at idle it seams to be coming from the main drive pulley. I guess I'm just looking for some possibilities on what it could be because I screw something up everytime I guess. All help appreciated.

[everett]

did you leave something loose maybe a bolt--try 2 tighten every thing up and see wat happens