So when my car is idle, 2002 Monte SS, it'll start up fine then it'll go up to 1500 rpm and start clicking loud, it'll go away if I get to say 3000 rpm so I dont know exactly what it could be except for the water pump pulley, I noticed it was vibrating a little when I popped the hood and checked, I turn off the engine and try moving it but its completely fine from what I can tell...

Anyone have any suggestions?

Thanks

Mic