I've got a slight rattle under the hood that is coming from a pulley. I'm pretty sure it's an idler pulley. How many do I have? I think I can hear the rattle coming from the pulley to the left of the alternator directly under the air intake. Thanks!

 

That sounds like the water pump. Take the belt off by putting a ratchet on the top pulley to the left act like your taking it off and it will release tension from the belt. After you get it off turn the pulleys by hand you if its a bad bearing you will feel it. It will feel like there is sand or something in it.

 

Sweet thanks for the help!