GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Avalanche - 4WD 🢒 Engine 🢒 Engine Mechanical - 4.8L, 5.3L, and 6.0L 🢒 Intake Manifold Replacement

Removal Procedure

    Important: The intake manifold, throttle body, fuel rail, and injectors may be removed as a complete 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 in Engine Controls - 4.8L, 5.3L, and 6.0L.
  2. Remove the fuel injectors. Refer to Fuel Injector Replacement in Engine Controls - 4.8L, 5.3L, and 6.0L.

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

    6. Object Number: 382483 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: 647793 Size: SH
  7. Remove the positive crankcase ventilation (PCV) hose with valve.

    8. Object Number: 863068 Size: SH
  8. Remove the MAP sensor (1) from the intake manifold.

    9. Object Number: 832127 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: 832132 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: 642285 Size: SH
  2. Install the intake manifold.
  3. Apply a 5 mm (0.20 in) band of threadlock GM P/N 12345382 (Canadian P/N 10953489), or equivalent to the threads of the intake manifold bolts.

    4. Object Number: 63222 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.

  4. Tighten the intake manifold bolts.

    5. Tighten

    1. Tighten the bolts a first pass in sequence to 5 N·m (44 lb in).
    2. 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: 832127 Size: SH
  6. Install the EVAP purge solenoid vent tube to the solenoid (1) and vapor pipe (2).

    7. Object Number: 863068 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: 647793 Size: SH
  8. Install the PCV hose with valve.

    9. Object Number: 382483 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. • The MAP sensor (1)
    • The knock sensor (2)
  13. Install the fuel injectors. Refer to Fuel Injector Replacement in Engine Controls - 4.8L, 5.3L, and 6.0L.
  14. Install the throttle body. Refer to Throttle Body Assembly Replacement in Engine Controls - 4.8L, 5.3L, and 6.0L.