GM Service Manual Online
For 1990-2009 cars only

Intake Manifold Replacement Upper

Removal Procedure


    Object Number: 175681  Size: SH
  1. Remove the engine cover from the vehicle. Refer to Engine Cover Replacement in Body and Accessory.
  2. Remove the air cleaner assembly from the vehicle. Refer to Air Cleaner Assembly Replacement in Engine Controls.
  3. Remove the air intake duct from the turbocharger.

  4. Object Number: 53797  Size: SH
  5. Remove the CDR valve from the air intake duct.
  6. Remove the electrical harness and retaining brackets from the upper intake manifold.
  7. Remove the transmission oil level indicator tube from the upper intake manifold.
  8. Remove the rear air conditioning line from the upper intake manifold (if equipped).

  9. Object Number: 68321  Size: SH

    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.

  10. Remove the upper intake manifold bolts.
  11. Remove the upper intake manifold and gaskets from the lower intake manifold.

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

    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.

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

  3. Install the electrical harness and retaining brackets to the upper intake manifold.
  4. Install the rear A/C line to the upper intake manifold (if equipped).
  5. Install the transmission oil level indicator tube to the upper intake manifold.

  6. Object Number: 175681  Size: SH
  7. Install the air intake duct to the turbocharger.
  8. Install the air cleaner assembly inn the vehicle. Refer to Air Cleaner Assembly Replacement in Engine Controls.
  9. Install the CDR valve to the air intake duct.
  10. Install the engine cover in the vehicle. Refer to Engine Cover Replacement in Body and Accessory.

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: 68323  Size: SH
  1. Disconnect the battery negative cable from the battery.
  2. • For the front battery, refer to Battery Cable Replacement in Engine Electrical.
    • For the auxiliary battery, refer to Battery Cable Replacement in Engine Electrical.
  3. Remove the upper intake manifold from the lower intake manifold. Refer to Intake Manifold Replacement .
  4. Remove the boost sensor relay from the lower intake manifold.
  5. Remove the glow plug relay from the lower intake manifold.
  6. Remove the fuel line retaining clips.
  7. Remove the electrical harness retaining clips and ground straps.
  8. Remove the lower intake manifold bolts and fuel line clips.
  9. Remove the lower intake manifold and gaskets from the cylinder heads.
  10. Inspect and clean the sealing surface on the cylinder heads.

Installation procedure


    Object Number: 68323  Size: SH

    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.

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

  3. Install the fuel line retaining clips.
  4. Install the electrical harness retaining clips and ground straps.
  5. Install the glow plug relay to the lower intake manifold.
  6. Install the boost sensor relay to the lower intake manifold.
  7. Install the upper intake manifold to the lower intake manifold. Refer to Intake Manifold Replacement .
  8. Connect the battery negative cables to the batteries.
  9. • For the front battery, refer to Battery Cable Replacement in Engine Electrical.
    • For the auxiliary battery, refer to Battery Cable Replacement in Engine Electrical.