GM Service Manual Online
For 1990-2009 cars only

Intake Manifold Replacement Upper

Removal Procedure

Important: Do not attempt to remove the upper intake manifold with the lower intake manifold as an assembly. The upper and lower intake manifolds will not align with the turbocharger or the bolt holes for either of the intake manifold bolts for reassembly.


    Object Number: 290910  Size: SH
  1. Remove the air cleaner assembly from the vehicle. Refer to Air Cleaner Assembly Replacement in Engine Controls-6.5L.
  2. Remove the air intake duct from the turbocharger.

  3. Object Number: 53797  Size: SH
  4. Remove the CDR valve from the right valve rocker arm cover (if needed).
  5. Remove the engine wiring harness from the upper intake manifold.
  6. Secure the engine wiring harness out of the way.

  7. Object Number: 68321  Size: SH
  8. Remove the upper intake manifold bolts.
  9. Remove the upper intake manifold from the turbocharger and the lower intake manifold.
  10. Remove the upper intake manifold and gaskets from the lower intake manifold.
  11. Remove the O-ring from the turbocharger.

Installation Procedure

Important: Always replace the O-ring between the upper intake manifold and the turbocharger. Coat the new O-ring with clean engine oil before installing on the turbocharger.


    Object Number: 68321  Size: SH
  1. Lightly coat the new O-ring with clean motor oil.
  2. Install the new gaskets between the upper and lower intake manifold.
  3. Install the upper intake manifold on the turbocharger and lower intake manifold.
  4. Important: Make sure that the upper intake manifold is seated properly on the turbocharger before installing the upper inatke manifold mounting bolts.

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  5. Install the upper intake manifold bolts
  6. Tighten
    Tighten the bolts to 23 N·m (17 lb ft).


    Object Number: 290910  Size: SH
  7. Install the engine wiring harness to the upper intake manifold.

  8. Object Number: 53797  Size: SH
  9. Install the CDR valve to the right valve rocker arm cover (if removed).
  10. Install the air intake duct to the turbocharger.
  11. Install the air cleaner assembly in the vehicle. Refer to Air Cleaner Assembly Replacement in Engine Controls-6.5L.

Intake Manifold Replacement Lower

Removal Procedure

Important: Do not attempt to remove the upper intake manifold with the lower intake manifold as an assembly. The upper and lower intake manifolds will not align with the turbocharger or the bolt holes for either of the intake manifold bolts for reassembly.


    Object Number: 53797  Size: SH
  1. Disconnect the battery negative cable from the batteries. Refer to Battery Replacement in Engine Electrical.
  2. Remove the air cleaner from the vehicle. Refer to Air Cleaner Assembly Replacement in Engine Controls-6.5L.
  3. Remove the air intake duct from the turbocharger.
  4. Remove the upper intake manifold from the lower intake manifold. Refer to Intake Manifold Replacement .
  5. Remove the CDR valve from the right valve rocker arm cover.
  6. Remove the boost sensor from the lower intake manifold. Refer to Boost Sensor Replacement in Engine Controls-6.5L.
  7. Remove the wastegate solenoid from the lower intake manifold. Refer to Wastegate Solenoid Replacement in Engine Controls-6.5L.

  8. Object Number: 293494  Size: SH
  9. Remove the ground wire from the right rear corner of the lower intake manifold.
  10. Remove the glow plug relay from the lower intake manifold. Refer to Glow Plug Relay Replacement in Engine Controls-6.5L.

  11. Object Number: 68323  Size: SH
  12. Remove the lower intake mounting bolts from the lower intake manifold.
  13. Remove the lower intake manifold mounting bolts from the cylinder heads.
  14. Remove the fuel injector lines from the retaining clips.
  15. Remove the retaining clips.
  16. Remove the lower intake manifold gasket from the cylinder heads.
  17. Inspect and clean the sealing surface on the cylinder heads.

Installation procedure


    Object Number: 68323  Size: SH
  1. Install the new lower intake manifold gasket to the cylinder heads.
  2. Install the lower intake manifold to the cylinder heads.
  3. Install the fuel line retaining clips to the lower intake manifold mounting bolts.
  4. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  5. Install the lower intake manifold bolts to the cylinder head.
  6. Tighten
    Tighten the bolts to 42 N·m (31 lb ft).

  7. Install the fuel lines to the retaining clips.
  8. Install the glow plug relay on the lower intake manifold. Refer to Glow Plug Relay Replacement in Engine Controls-6.5L.

  9. Object Number: 293494  Size: SH
  10. Install the ground wire to the right rear corner of the lower intake manifold.
  11. install the wastegate solenoid on the lower intake manifold. Refer to Wastegate Solenoid Replacement in Engine Controls-6.5L.
  12. Install the boost sensor on the lower intake manifold. Refer to Boost Sensor Replacement in Engine Controls-6.5L.
  13. Install the upper intake manifold to the lower intake manifold. Refer to Intake Manifold Replacement .

  14. Object Number: 53797  Size: SH
  15. Install the CDR valve in the right valve rocker arm cover.
  16. Install the air intake duct on the turbocharger.
  17. Install the air cleaner in the vehicle. Refer to Air Cleaner Assembly Replacement in Engine Controls-6.5L.
  18. Connect the battery negative cables to the batteries. Refer to Battery Replacement in Engine Electrical.