WARNING: This page is about a different car, the 2003 Pontiac Aztek and 2003 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
Inspect the crankshaft balancer sealing area for grooves (1).
Inspect the crankshaft balancer belt ribs for dents or damage.
Replace the crankshaft balancer if necessary.
Fig 1: Identifying Crankshaft Balancer Sealing Area For Grooves Inspection