It's probably an idler pulley. Noise from hem isn't all that uncommon.
Also, when my water pump went and got some coolant on the belt, the rubber absorbed enough of it that I had to replace the belt. It didn't matter how I tried cleaning it, as soon as it got too damp outside, it would start squealing.
Also, when my water pump went and got some coolant on the belt, the rubber absorbed enough of it that I had to replace the belt. It didn't matter how I tried cleaning it, as soon as it got too damp outside, it would start squealing.