Yesterday I got a can of STP Belt Conditioner. I sprayed it on the water pump pulley as it was the only one easily accessible while the motor was running. I got instant quiet!
The deflection on the belt is about 3/8 inch on a foot or so free section. I wonder if something was deposited on the pulley during our 18 inch snow storm and subsequent salting and the like of the roads. I've read during my googling that foreign material on the belt may have this effect.
Its due for a 12500 Mile oil change. I'll ask them to check if anything is wrong. Big bucks for this check?
Al