Noise coming from Serpentine belt/pulley area

Hey everyone! Just wondering if anyone can help me diagnose a small problem with my 2000 Ford Mustang GT (4.6L with 138,800 miles). When I started my mustang lately, there's a sound coming from the serpentine belt/pulley area in front of my engine. It sounds like one of the pulleys are loose or something, but not sure. Has anyone else had this problem before?
 
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What kind of noise is it? Is it coming from left side, right side, or middle? If you have a stethoscope that would be helpful, if not, take a really long screwdriver and place the point on the bolt that holds the pulley on and place your ear on the butt end and listen. If it sounds different than the others, then that's your problem area. Also pull straight up on your belt and check the tensioner. You should have a little movement, but nothing excessive. And now would also be a good time to check the condition of the belt. Check for cracks along the ribs, pieces broken off, and frayed edges. I'll post back if I can think of anything else.
 
Noise coming from Serpentine belt/pulley area Reply to Thread

Thanks 2002SN95MUSTANG! I'll give the stethascope a try :D
The noise sounds like it's coming from a pulley on the passenger side. As far as how the noise sounds, it sounds like the pulley is loose as it's spinning (like the pulley is rubbing up against some metal surface as it's spinning). The noise isn't very loud, but it's loud enough to be noticeable with the engine running at idle. I'm very seriously considering changing the serpentine belt too, as I have not changed it since owning the car (9 years, 138,800 miles) oops :(
 
An easy diagnosis and fix. Take the tension off the belt (via a 3/8 ratchet and the belt tensioner) and remove it. Then, reach in and spin all of your idler pullies by hand. If they're loose, or sound like they're full of sand, the bearing is worn out and needs to be replaced as it is likely the source of your noise. While the belt is off, inspect it visually. If there's any noticeable wear, rips, or cracks in the belt, replace it. If not, put on a pair of rubber gloves, get yourself an old pickle bucket and go to town on it with a scrub brush, some scalding hot water and some Ivory dish soap.

While the belt is off, this would be a good time to inspect your water pump and power steering pump to ensure they're not leaking and leaving any residue on the belt.

Assuming all is well with the other components, reapply the belt (or install the new on if necessary), start it up…bring it up to operating temperature and take if for a ride.
 
Yea, what Gearbanger said. Mine did this back in the summer. The bearing in my tensioner pulley was going out. You can't just replace the bearing; you actually have to replace the entire pulley. I went ahead and replaced the tensioner pulley, idler pulley (the 2 are the same size, or at least on my Romeo motor), and the belt. Haven't heard a peep since.

-Will