serpentine belt or pully
 

I have what sounds like a belt noise in my 97 lesabre only when the engine is warm and at adle. If I kill lthe engine and restart the noise goes away. Turning the wheel or turning the ac off and on has no effect. Is this a belt noise or a pully? The car was recently detailed and the belt was sprayed with silicone. The noise has gotten worse since then.

It could just be the belt slipping a little due to the silicone. Was it making the noise before the detail?

Sometimes spraying some water on the belt with a hose will help get rid of the noise just be careful doing this with the engine running because you will get sprayed back if you are standing too close.