GM Service Manual Online
For 1990-2009 cars only
    • A/C compressor or generator bearing. Replace as necessary.
    • Valve train. Replace parts as necessary.
    • Improper oil viscosity. Replace with the proper oil for expected temperature.
    • Connecting rod alignment. Replace the connecting rods as necessary.
    • Excessive piston pin clearance.
    • Loose crankshaft balancer. Torque and/or replace.
    • Piston pin offset to wrong side. Install correct piston.
    • Dirt of foreign material lodged in the balance shaft gear or the camshaft gear.