GM Service Manual Online
For 1990-2009 cars only
  1. Clean the parts in solvent, removing all sludge and varnish.
  2. Clean the old sealer from the sealing surfaces.
  3. Inspect for the following conditions:
  4. • Bent or damaged sealing flanges
    • Deterioration of the rubber grommets or parts on the valve rocker arm cover
    • Damage to the oil pan caused by rocks
    • Loose fit of the oil pan baffle
    • Stripped oil pan drain plug opening threads