1999 Cadillac Escalade Cadillac Escalade

There's two common things to look for. First is when there's a spring-loaded tensioner pulley, be sure it moves freely when you tug on the belt and release it. If it sticks or won't move at all, it won't keep proper tension on the belt.

Next is to look for any pulley that's tipped or turned. That will make the belt slide across it as it goes around it and will set up a horrendous squeal. If you see the belt peeking out where it's not in line with where it goes around the other pulleys, that pulley or the one right before it is tipped or turned.

Be sure to never use any type of belt dressing on a serpentine belt. If you did, replace the belt again after washing and scrubbing all of the pulleys with an engine degreaser.