The serpentine belt keeps shredding off on the engine side (one groove at a time). I replaced both the number two idler pulleys that were making noise. Not sure why the belt is still coming apart. I think it might be the belt tensioner.
Hi. A malfunctioning belt tensioner is likely, as well as other component along the belt drive system, to cause failure with the belt. Have a technician remove the belt and make sure all of the other components spin freely at the pulley. The technician will be able to determine if the belt is shredding due to misalignment. The repair cannot be complete without replacing the shredded belt as well. Once the drive belt starts to deteriorate, its life is shortened dramatically. If you need further assistance, I recommend you have a certified technician, like one from YourMechanic, replace the serpentine belt and inspect the pulleys to make sure they are not extremely hard to move, as this can cause your belt to deteriorate.