GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2009 🢒 G8 🢒 Preface 🢒 Dangers, Warnings, and Cautions 🢒 Lower Intake Manifold Replacement

    Warning: Refer to Battery Disconnect Warning in the Preface section.

  1. Disconnect the battery ground cable. Refer to Battery Negative Cable Disconnection and Connection.
  2. Remove the engine covers. Refer to Engine Cover Replacement.
  3. Remove the air intake duct. Refer to Air Cleaner Inlet Duct Replacement.

    4. Object Number: 1957956 Size: SH
  4. Disconnect the throttle body electrical connector (1).

    5. Object Number: 1957963 Size: SH
  5. Disconnect the brake booster vacuum hose (2) from the intake manifold (1).

    6. Object Number: 1957965 Size: SH
  6. Disconnect the Inlet Manifold Runner Control (IMRC) solenoid connector (1).

    7. Object Number: 1957968 Size: SH
  7. Disconnect the evaporative emission (EVAP) purge line (1) from the purge solenoid (2). Refer to Metal Collar Quick Connect Fitting Service or Plastic Collar Quick Connect Fitting Service.
  8. Plug or cap the (EVAP) purge line (1) and the purge solenoid (2) ends.
  9. Remove the PCV tube and PCV fresh air tubes. Refer to Positive Crankcase Ventilation Hose/Pipe/Tube Replacement.

    10. Object Number: 1957970 Size: SH
  10. Disconnect the EVAP valve electrical connector (4)
  11. Disconnect the fuel injector harness electrical connector (3)
  12. Remove the fuel injector harness electrical connector/EVAP valve mounting bracket to intake manifold retaining bolt (2).
  13. Reposition the fuel injector harness electrical connector/EVAP valve mounting bracket (5) away from the intake manifold (1).

    14. Object Number: 1957976 Size: SH
  14. Disconnect the fuel feed pipe (2) from the fuel rail (1). Refer to Metal Collar Quick Connect Fitting Service or Plastic Collar Quick Connect Fitting Service.

    15. Note: Plug or cap the fuel feed pipe (2) and fuel rail (1) ends to prevent fuel leaks and/or contamination.

  15. Plug or cap the fuel feed pipe (2) and fuel rail (1) ends.

    16. Object Number: 1957973 Size: SH
  16. Disconnect the EVAP line (1) from the intake manifold (2).

    17. Object Number: 1957978 Size: SH

    Note: 

       • DO NOT remove the upper intake manifold to lower intake manifold retaining bolts (3).
       • DO NOT kink or damage the fuel pipe.

  17. Remove the intake manifold to cylinder head retaining bolts (1).
  18. Remove the intake manifold assembly (2).

    19. Note: The cylinder heads and engine valley must be plugged with a clean lint free cloth to prevent foreign matter entry into the engine.

  19. Plug the cylinder heads and engine valley with a clean lint free cloth.
  20. Disassemble the intake manifold as to replace the lower intake manifold. Refer to Intake Manifold Disassemble.
  21. Clean and inspect the intake manifold and the sealing surfaces. Refer to Intake Manifold Cleaning and Inspection.

Installation Procedure
  1. Assemble the intake manifold as necessary. Refer to Intake Manifold Assemble.
  2. Remove the clean lint free cloth from the cylinder heads and engine valley.

    3. Object Number: 1961739 Size: SH

    Note: Inspect and replace the lower intake manifold gasket only if the gasket is worn or damaged.

  3. Install the lower intake manifold gasket.

    4. Object Number: 1957978 Size: SH
  4. Install the intake manifold assembly (2).

    5. Caution: Refer to Fastener Caution in the Preface section.

    Note: Tighten the intake manifold to cylinder head retaining bolts (1) in a circular pattern starting at the center (long bolts) and moving outward.

  5. Install the intake manifold using the cylinder head retaining bolts (1) and tighten to 23 N·m (17 lb ft).

    6. Object Number: 1957973 Size: SH
  6. Connect the EVAP line (1) to the intake manifold (2).

    7. Object Number: 1957976 Size: SH
  7. Remove the plug or cap at the fuel feed pipe (1) and fuel rail (2) ends
  8. Connect the fuel feed pipe (1) to the fuel rail (2). Refer to Metal Collar Quick Connect Fitting Service or Plastic Collar Quick Connect Fitting Service.

    9. Object Number: 1957970 Size: SH
  9. Install the fuel injector harness electrical connector/EVAP valve mounting bracket (5) to the intake manifold (1).
  10. Install the fuel injector harness electrical connector/EVAP valve mounting bracket to intake manifold retaining bolt (2).
  11. Connect the fuel injector harness electrical connector (3)
  12. Connect the EVAP valve electrical connector (4)
  13. Install the PCV tube and PCV fresh air tubes. Refer to Positive Crankcase Ventilation Hose/Pipe/Tube Replacement.

    14. Object Number: 1957968 Size: SH
  14. Remove the plug or cap from the (EVAP) purge line (2) and the purge solenoid (1) ends.
  15. Connect the evaporative emission (EVAP) purge line (2) from the purge solenoid (1). Refer to Metal Collar Quick Connect Fitting Service or Plastic Collar Quick Connect Fitting Service.

    16. Object Number: 1957965 Size: SH
  16. Connect the Inlet Manifold Runner Control (IMRC) electrical connector (1).

    17. Object Number: 1957963 Size: SH
  17. Connect the brake booster vacuum hose (2) to the intake manifold (1).

    18. Object Number: 1957956 Size: SH
  18. Connect the throttle body electrical connector (1).
  19. Install the air intake duct. Refer to Air Cleaner Inlet Duct Replacement.
  20. Install the engine covers. Refer to Engine Cover Replacement.
  21. Connect the battery ground cable. Refer to Battery Negative Cable Disconnection and Connection.