Belt squeals can be a royal PIA to track down. First you said that you replaced the belt/tensioner. Did you buy a cheap belt or a quality one? With a serpentine belt the quality of the belt is a BIG item.
Next make SURE the noise is the belt. Release the tensioner and take the belt off of the idler on top. Now start the engine and see if the noise is gone. If yes then you get to track down the problem. One thing I like to do is to clean the pulleys with some acetone or alcohol, then use a stiff wire brush to scuff them some. They can get road grime/dirt/oil/antifreeze on them and make small glazed ares that cause problems. Then rotate each pulley and idler. Listen for loud noise. grinding , squeaks. Also feel as you do that for rough bearings or loose bearings.
Good luck.
Dec 4, 2009 at 3:05 PM
