GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 GMC C Sierra - 2WD 🢒 Engine 🢒 Engine Electrical 🢒 Intake Manifold Replacement

Removal Procedure

    Important: The intake manifold, throttle body, fuel rail, and injectors may be removed as an assembly. If not servicing the individual components, remove the manifold as a complete assembly.

  1. Remove the throttle body. Refer to Throttle Body Assembly Replacement .
  2. Remove the fuel injectors. Refer to Fuel Injector Replacement .

    3. Object Number: 679510 Size: SH
  3. Disconnect the following electrical connectors:
    4. • Manifold absolute pressure (MAP) sensor (1)
    • Knock sensor (2)
  4. Remove the knock sensor harness electrical connector from the intake manifold.
  5. Set the electrical harness aside.

    6. Object Number: 1236362 Size: SH
  6. If equipped with vacuum assisted brakes, remove the vacuum brake booster hose from the rear of the intake manifold.

    7. Object Number: 1201537 Size: SH
  7. Remove the positive crankcase ventilation (PCV) hose.

    8. Object Number: 1201538 Size: SH
  8. Remove the MAP sensor (1) from the intake manifold.

    9. Object Number: 1285743 Size: SH
  9. Remove the evaporative emission (EVAP) purge solenoid vent tube by performing the following:
    10. 9.1. Remove the EVAP tube end from the solenoid (1).
    9.2. Remove the EVAP tube end from the vapor pipe (2).

    Object Number: 389993 Size: SH
  10. Remove the EVAP purge solenoid bolt (2), solenoid (3), and isolator (1) from the intake manifold.

    11. Object Number: 1201541 Size: SH
  11. Loosen the intake manifold bolts.
  12. Remove the intake manifold.

    13. Object Number: 492770 Size: SH
  13. Remove the intake manifold gaskets (1) from the intake manifold.
  14. Discard the old intake manifold gaskets.
  15. If required, clean and inspect the intake manifold. Refer to Intake Manifold Cleaning and Inspection .

Installation Procedure

    Object Number: 492770 Size: SH
  1. Install NEW intake manifold gaskets (1) to the intake manifold.

    2. Object Number: 1201541 Size: SH
  2. Install the intake manifold.
  3. Apply a 5 mm (0.2 in) band of threadlocker to the threads of the intake manifold bolts. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.

    4. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 63222 Size: SH
  4. Tighten the intake manifold bolts.

    5. Tighten

        • Tighten the bolts a first pass in sequence to 5 N·m (44 lb in).
        • Tighten the bolts a final pass in sequence to 10 N·m (89 lb in).

    Object Number: 389993 Size: SH
  5. Install the EVAP purge solenoid (3), isolator (1), and bolt (2) to the intake manifold.

    6. Tighten
    Tighten the bolt to 10 N·m (89 lb in).


    Object Number: 1285743 Size: SH
  6. Install the EVAP purge solenoid vent tube to the solenoid (1) and vapor pipe (2).

    7. Object Number: 1201538 Size: SH

    Important: Lightly coat the MAP sensor seal with clean engine oil before installing.

  7. Install the MAP sensor (1) to the intake manifold.

    8. Object Number: 1201537 Size: SH
  8. Install the PCV hose.

    9. Object Number: 1236362 Size: SH
  9. If equipped with vacuum assisted brakes, install the vacuum brake booster hose to the rear of the intake manifold.
  10. Route the electrical harness into position over the engine.

    11. Object Number: 679510 Size: SH
  11. Connect the knock sensor harness electrical connector to the intake manifold.
  12. Connect the following electrical connectors.
    13. • MAP sensor (1)
    • Knock sensor (2)
  13. Install the fuel injectors. Refer to Fuel Injector Replacement .
  14. Install the throttle body. Refer to Throttle Body Assembly Replacement .