GM Service Manual Online
For 1990-2009 cars only

Completely inspect the turbocharger and all other engine components that may cause similar conditions before replacing the turbocharger.

Use the following information to diagnose problems caused by the turbocharger.

The turbocharger is serviced as a complete unit.


    Object Number: 1336136  Size: SH

    Note: Oil residue on the turbocharger compressor wheel is normal with a closed PCV system.

  1. Remove the turbocharger oil return pipe bolts.
  2. Remove the turbocharger oil return pipe and gasket.
  3. Clean mating surfaces.

  4. Object Number: 177078  Size: SH
  5. Inspect for damage to the compressor wheel, compared to a normal compressor wheel.

  6. Object Number: 177081  Size: SH
  7. Inspect for damage to the compressor wheel, by a soft object.

  8. Object Number: 177083  Size: SH
  9. Inspect for damage to the compressor wheel, by a hard object.

  10. Object Number: 177086  Size: SH
  11. Inspect compressor blades for heavy rubbing.
  12. Ensure that the following conditions do not exist on the compressor wheel blades:

    • Cracks
    • Bends
    • Erosion of the blades
    • Broken blades
  13. Check the housing for signs of rubbing.

  14. Object Number: 1336136  Size: SH
  15. Install the turbocharger oil return pipe and new gasket.
  16. Caution: Refer to Fastener Caution in the Preface section.

  17. Install the turbocharger oil return pipe bolts and tighten to 21 N·m (15 lb ft).

  18. Object Number: 1457469  Size: SH

    Note: If the cooling outlet hose eye bolts were removed, install the longer bolt (1) with two holes, in the top location. Install the shorter bolt (2) in the lower location.

  19. Inspect the coolant outlet lines for damage.

  20. Object Number: 1336139  Size: SH
  21. Clean the turbocharger inlet duct.
  22. Clean the turbocharger inlet duct mating surfaces.
  23. Inspect the turbocharger inlet duct for cracks.
  24. Inspect the turbocharger inlet duct mating surfaces for damage.
  25. Replace the turbocharger inlet duct if any damage is found and tighten the inlet duct clamp to 5 N·m (44 lb in).