GM Service Manual Online
For 1990-2009 cars only
  1. Clean all of the parts in cleaning solvent. Dry the parts with compressed air.
  2. Inspect the following areas:
  3. • The oil pump housing and cover for cracks, scoring, casting imperfections, and damaged threads
    • The drive gear shaft (If the shaft is loose in the oil pump housing, replace the oil pump.)
    • The pressure relief valve for scoring and sticking (Burrs may be removed with a fine oil stone.)
    • The relief valve spring for loss of tension
    • The oil pump screen for broken wire mesh or looseness (If the pipe is loose or has been removed from the screen, the oil pump screen must be replaced.)
    • The gears for chipping, galling, and wear

       Important: If the drive gear and driveshaft are worn, replace the entire oil pump.

    • The drive gear and driveshaft for looseness and wear