The serpentine belt tensioner pulley may wear out. Our technicians tell us that in order to get a new pulley from General Motors you must purchase a complete belt tensioner assembly.
Average mileage: 130,044 (55,134–175,000)
Engines affected: 3.1L V6, 3.8L V6
5 people reported this problem
I replaced broken belt then the belt broke again after 2 months. I didn't notice anything at the time so I replaced it again. After about 15 minutes of driving, I could hear the belt shredding again. The tensioner was bouncing and needed to be replaced. Unfortunate thing is that when the belt broke, it tore into my CV boot, which also required replacement.