Originally Posted By: GMBoy
Check the alignment of the pulleys. Sounds like one or more may be off. This would stress the bearings and/or the idler pulley and cause early failure. The fact that you've had this happen 3 times indicates something is out of alignment. How does the belt look? Is it chewed up?
Now that you mention it, the idler on my mother's Sunfire 2.4L seemed to be squealing a bit couple of months ago. She complained about a noise, so I looked at the belt, and it looked good and was riding properly on all the grooved pulleys. I then pulled the belt off and the idler seemed fine when I spun it with my fingers, so I started it up without the belt to make sure it wasn't something else. No noise. When I put the belt back on, the noise was gone and hasn't returned. This all happened a couple of weeks after reinstalling the belt following a water pump replacement (timing chain driven), so I did consider the possibility that the belt wasn't riding properly on the pulley, but dismissed the idea because I thought it would self-correct and return to its natural state regardless.