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Oil Pump Cleaning and Inspection

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
    Fig 1: Measuring Inner Rotor-To-Outer Rotor Clearance
    GM897218Courtesy of GENERAL MOTORS CORP.
  1. Disassemble the oil pump. Refer to Oil Pump Disassemble .
  2. Measure the inner-to-outer rotor radial clearance. Use a feeler gage to measure between the inner rotor (432) and the outer rotor (433).

    If the clearance exceeds the service limit, replace the oil pump assembly.

    Specification: 

    • Oil pump inner rotor-to-outer rotor radial clearance - new: 0.04-0.16 mm (0.002-0.0063 in)
    • Oil pump inner rotor-to-outer rotor radial clearance - service limit: 0.2 mm (0.008 in)

  3. Fig 2: Measuring Housing-To-Rotor Axial Clearance
    GM897219Courtesy of GENERAL MOTORS CORP.
  4. Measure the housing-to-rotor axial clearance. Use a feeler gage and a straight edge to measure between both rotors (1) and the straight edge.

    If the clearance exceeds the service limit, replace the oil pump assembly.

    Specification: 

    • Housing-to-rotor axial clearance - new: 0.02-0.07 mm (0.001-0.003 in)
    • Housing-to-rotor axial clearance - service limit: 0.12 mm (0.005 in)

  5. Fig 3: Measuring Outer Rotor-To-Pump Housing Clearance
    GM897221Courtesy of GENERAL MOTORS CORP.
  6. Measure the housing-to-outer rotor radial clearance. Use a feeler gage to measure between the outer rotor (433) and the pump housing (424).

    If the clearance exceeds the service limit, replace the oil pump assembly.

    Specification: 

    • Housing-to-outer rotor radial clearance - new: 0.10-0.19 mm (0.004-0.007 in)
    • Housing-to-outer rotor radial clearance - service limit: 0.2 mm (0.008 in)

  7. Fig 4: Exploded View Of Oil pump Assembly
    GM897001Courtesy of GENERAL MOTORS CORP.
  8. Inspect both rotors (432 and 433) for scoring or other damage.
  9. Inspect the valve (420) and valve bore for scoring or other damage. The valve must move freely in the bore.
  10. Inspect for a collapsed or broken spring (421).
  11. Inspect the sealing surfaces for damage.
  12. Inspect the oil passages for debris or restrictions.
  13. Assemble the oil pump. Refer to Oil Pump Assemble .