Now that I just replaced my serpentine belt, I have to say it is really LOUD. Maybe that is a good way to tell when it's getting ready to be replaced. It is LOUD now.

I did a search and can't find it. I remember someone talking about a aftermarket belt that was very cheap, just want to keep a spare under the back seat.

 

Try this link. It's for a Goodyear Gatorback belt for truck with A/C. Price has gone up though, was about $29.00 before I think.

http://www.autozone.com/N,15300077/s...eResultSet.htm

 

It might be your belt tensioner making the noise.

 

On my old chevy, the belt tensioner bearing went out and it got really loud. that would be my first place to check.