GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2006 🢒 TrailBlazer - 2WD 🢒 Engine 🢒 Engine Mechanical - 5.3L 🢒 Intake Manifold Replacement

Removal Procedure
  1. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .

    2. 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.

  2. Remove the air cleaner outlet duct. Refer to Air Cleaner Resonator Outlet Duct Replacement .
  3. Relieve the fuel system pressure. Refer to Fuel Pressure Relief .

    4. Object Number: 898468 Size: SH
  4. Disconnect the air conditioning (A/C) compressor pressure switch electrical connector (2).
  5. Remove the harness clip (1) from the cylinder head.

    6. Object Number: 1204792 Size: SH
  6. Disconnect the electrical connector (1) from the mass air flow (MAF)/intake air temperature (IAT) sensor.
  7. Remove the harness clips from the fuel rail.

    8. Object Number: 1209783 Size: SH
  8. Perform the following steps in order to disconnect the fuel injector electrical connectors.
    9. 8.1. Mark the connectors to their corresponding injectors to ensure correct reassembly.
    8.2. Pull the connector position assurance (CPA) retainer (2) on the connector up one click.
    8.3. Push the tab (1) on the connector in.
    8.4. Disconnect the fuel injector electrical connector.
    8.5. Repeat the steps for each injector electrical connector.

    Object Number: 1618062 Size: SH
  9. Disconnect the following electrical connectors:
    10. • Evaporative emission (EVAP) purge solenoid (3)
    • Throttle body harness (5)
    • Manifold absolute pressure (MAP) sensor (2)
    • Main coil (1)
    • Generator (4)
  10. Remove the electrical harness clips from the fuel rail.

    11. Object Number: 1485981 Size: SH
  11. Remove the positive crankcase ventilation (PCV) hose.

    12. Object Number: 898349 Size: SH
  12. Remove the heater water shutoff valve actuator inlet hose from the intake manifold.

    13. Object Number: 1485982 Size: SH
  13. Remove the EVAP purge solenoid vent tubes (1, 2). Refer to Plastic Collar Quick Connect Fitting Service .

    14. Object Number: 1366114 Size: SH
  14. Disconnect the fuel feed pipe (3) from the fuel rail (2). Refer to Metal Collar Quick Connect Fitting Service .

    15. Object Number: 898352 Size: SH
  15. Remove the vacuum brake booster hose from the rear of the intake manifold.

    16. Object Number: 899740 Size: SH
  16. Remove the upper engine wire harness retainer nut (1).
  17. Reposition the upper engine wire harness aside.

    18. Object Number: 1618083 Size: SH
  18. Remove the intake manifold bolts.
  19. Remove the intake manifold.

    20. Object Number: 492770 Size: SH
  20. Remove the intake manifold gaskets (1) from the intake manifold.
  21. Discard the old intake manifold gaskets.
  22. If necessary, 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: 1618083 Size: SH
  2. Install the intake manifold.
  3. Apply a 5 mm (0.2 in) bead of threadlock 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. Install 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: 899740 Size: SH
  5. Route the electrical harness into position over the engine.
  6. Install the engine harness bracket nut (1).

    7. Tighten
    Tighten the nut to 10 N·m (89 lb in).


    Object Number: 898352 Size: SH
  7. Install the vacuum brake booster hose to the rear of the intake manifold.

    8. Object Number: 1366114 Size: SH
  8. Connect the fuel feed pipe (3) to the fuel rail (2). Refer to Metal Collar Quick Connect Fitting Service .

    9. Object Number: 1485982 Size: SH
  9. Install the EVAP purge solenoid vent tubes (1, 2). Refer to Plastic Collar Quick Connect Fitting Service .

    10. Object Number: 898349 Size: SH
  10. Install the heater water shutoff valve actuator inlet hose to the intake manifold.

    11. Object Number: 1485981 Size: SH
  11. Install the PCV hose.
  12. Connect the electrical harness clips to the fuel rail.

    13. Object Number: 1618062 Size: SH
  13. Connect the following electrical connectors:
    14. • EVAP purge solenoid (3)
    • Throttle body harness (5)
    • MAP sensor (2)
    • Main coil (1)
    • Generator (4)

    Object Number: 1209783 Size: SH
  14. Perform the following steps in order to connect the fuel injector electrical connectors.
    15. 14.1. Install the connectors to their corresponding injectors to ensure correct reassembly.
    14.2. Connect the fuel injector electrical connector.
    14.3. Push the CPA retainer (2) on the connector in one click.
    14.4. Repeat the steps for each injector electrical connector.
  15. Install the electrical harness clips to the fuel rail.

    16. Object Number: 898468 Size: SH
  16. Connect the A/C compressor pressure switch electrical connector (2).
  17. Install the harness clip (1) to the cylinder head.

    18. Object Number: 1204792 Size: SH
  18. Connect the MAF/IAT sensor electrical connector (1).
  19. Install the air cleaner outlet duct. Refer to Air Cleaner Resonator Outlet Duct Replacement .
  20. Install the fuel fill cap.
  21. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  22. Use the following procedure in order to inspect for leaks:
    23. 22.1. Turn the ignition ON, with the engine OFF, for 2 seconds.
    22.2. Turn the ignition OFF for 10 seconds.
    22.3. Turn the ignition ON, with the engine OFF.
    22.4. Inspect for fuel leaks.