GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Blazer - 4WD - RHD 🢒 Engine 🢒 Engine Mechanical - 4.3L 🢒 Upper Intake Manifold Replacement

Removal Procedure

Important: The upper intake does not have to be removed to remove the lower intake manifold.


    Object Number: 444792 Size: SH
  1. Disconnect the breather tube at the air cleaner outlet duct.

    2. Object Number: 312278 Size: SH
  2. Remove the air cleaner outlet duct retaining wingnut.

    3. Object Number: 10940 Size: SH
  3. Disconnect the IAT sensor harness connector.

    4. Object Number: 424556 Size: SH
  4. Remove the air cleaner outlet duct from the throttle body.

    5. Object Number: 325556 Size: SH
  5. Disconnect the accelerator cable from the throttle body.

    6. Object Number: 616725 Size: SH
  6. Remove the accelerator cable from the accelerator control cable bracket.

    7. Object Number: 616709 Size: SH
  7. Remove the accelerator cable from the cable routing bracket.
  8. Disconnect the cruise control cable, if equipped from the throttle shaft and the accelerator cable bracket. Refer to Cruise Control Cable Replacement in Cruise Control.

    9. Object Number: 346148 Size: SH
  9. Disconnect the vacuum hose from the intake manifold for the vacuum tank.
  10. Remove the power brake booster vacuum hose.

    11. Object Number: 516898 Size: SH
  11. Disconnect the following electrical connectors:
    12. • The A/C compressor clutch (1)
    • The A/C compressor cutoff switch (5), if equipped
    • The throttle position (TP) sensor (2)
    • The idle air control (IAC) motor (3)

    Object Number: 516916 Size: SH
  12. Disconnect the following electrical connectors:
    13. • The fuel meter body assembly (1)
    • The manifold absolute pressure (MAP) sensor (3)
    • The EVAP canister purge solenoid valve (2)
  13. Remove the engine wire harness clip from the accelerator cable bracket.
  14. Move the engine wiring harness aside.

    15. Object Number: 398027 Size: SH
  15. Remove the accelerator cable bracket from the throttle body and the intake manifold.

    16. Object Number: 339439 Size: SH
  16. Remove the accelerator and cruise control cable bracket from the throttle body.

    17. Leave the accelerator and cruise control cables on the bracket.


    Object Number: 172995 Size: SH
  17. Remove the PCV valve hose assembly from the intake manifold and the valve rocker arm cover.

    18. Object Number: 339442 Size: SH
  18. Remove the bracket for the engine wiring harness from the intake manifold stud.
  19. Remove the fuel lines from the fuel meter body assembly. Refer to Fuel Hose/Pipes Replacement - Engine Compartment in Engine Controls - 4.3L.
  20. Remove the EVAP canister purge solenoid valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement in Engine Controls - 4.3L.

    21. Object Number: 516794 Size: SH
  21. Remove the studs for the upper intake manifold.
  22. Remove the upper intake manifold.

    23. Object Number: 516790 Size: SH
  23. Remove the upper intake manifold gasket from the groove.
  24. Discard the gasket.

    25. Object Number: 516773 Size: SH
  25. Remove the seal from the fuel meter body assembly.
  26. Discard the seal.

    27. Important: Do not immerse the assembled upper intake manifold in cleaning solvent.

  27. Clean all sealing surfaces and the inside of the upper intake manifold with a shop towel and cleaning solvent.
  28. Inspect the upper intake manifold for the following:
    29. • Cracks or other damage to the exterior
    • Cracking or damage to the gasket grooves
    • Loose or damaged bolt hole thread inserts
    • Damage to the throttle body mounting surface

    Object Number: 516804 Size: SH
  29. If replacing the upper intake manifold, turn and remove the power brake booster vacuum tube fitting from the upper intake manifold.
  30. Remove and discard the seal.

    31. Object Number: 516797 Size: SH
  31. If replacing the upper intake manifold, turn and remove the PCV valve cover from the upper intake manifold.
  32. Remove and discard the seal.
  33. Remove the throttle body if replacing the upper intake manifold. Refer to Throttle Body Assembly Replacement in Engine Controls - 4.3L.
  34. Remove the MAP sensor if replacing the upper intake manifold. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls - 4.3L.

Installation Procedure

    Object Number: 516797 Size: SH
  1. Install the throttle body, if removed. Refer to Throttle Body Assembly Replacement in Engine Controls - 4.3L.
  2. Install the MAP sensor, if removed. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls - 4.3L.
  3. Install the PCV valve cover, if removed, using the following procedure:
    4. 3.1. Install a NEW seal (O-ring) on the PCV valve cover.
    3.2. Lubricate the seal with clean engine oil.
    3.3. Install the PCV valve cover in the upper intake manifold.
    3.4. Turn and lock the PCV valve cover in position.

    Object Number: 516804 Size: SH
  4. Install the power brake booster vacuum tube fitting, if removed, using the following procedure:
    5. 4.1. Install a NEW seal (O-ring) on the power brake booster vacuum tube fitting.
    4.2. Lubricate the seal with clean engine oil.
    4.3. Install the power brake booster vacuum tube fitting in the upper intake manifold.
    4.4. Turn and lock the power brake booster vacuum tube fitting in position.

    Object Number: 516773 Size: SH
  5. Install a NEW seal on the fuel meter body assembly.
  6. Lubricate the seal with clean engine oil.

    7. Object Number: 516790 Size: SH
  7. Install a NEW upper intake manifold to lower intake manifold gasket in the groove of the upper intake manifold.

    8. Object Number: 516794 Size: SH
  8. Install the upper intake manifold onto the lower intake manifold.
  9. If reusing the fasteners, apply threadlock GM P/N 12345382 or equivalent to the threads of the upper intake manifold attaching bolts.

    10. 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.

  10. Install the upper intake manifold attaching studs.

    11. Tighten

    1. Tighten the upper intake manifold attaching studs on the first pass to 5 N·m (44 lb in).
    2. Tighten the upper intake manifold attaching studs on the final pass to 9 N·m (80 lb in).
  11. Install the fuel lines to the fuel meter body assembly. Refer to Fuel Hose/Pipes Replacement - Engine Compartment in Engine Controls - 4.3L.
  12. Install the EVAP canister purge solenoid valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement in Engine Controls - 4.3L.

    13. Object Number: 339442 Size: SH
  13. Install the bracket for the engine wiring harness on the lower intake manifold stud.
  14. Install the engine wiring harness bracket nut.

    15. Tighten
    Tighten the engine wiring harness bracket nut to 12 N·m (106 lb in).


    Object Number: 339439 Size: SH
  15. Install the accelerator and cruise control cable bracket to the throttle body.
  16. Install the accelerator and cruise control cable bracket nuts.

    17. Tighten
    Tighten the accelerator and cruise control cable bracket nuts to 9 N·m (80 lb in).


    Object Number: 398027 Size: SH
  17. Install the accelerator control cable bracket to the throttle body and the intake manifold.

    18. Tighten
    Tighten the accelerator control cable bracket studs and nuts to 12 N·m (106 lb in).


    Object Number: 172995 Size: SH
  18. Connect the PCV valve hose assembly to the intake manifold and the valve rocker arm cover.

    19. Object Number: 516916 Size: SH
  19. Position the engine wiring harness.
  20. Install the wire harness clip to the accelerator cable bracket.
  21. Connect the following electrical connectors:
    22. • The fuel meter body assembly (1)
    • The manifold absolute pressure (MAP) sensor (3)
    • The EVAP canister purge solenoid valve (2)

    Object Number: 516898 Size: SH
  22. Connect the following electrical connectors:
    23. • The A/C compressor clutch (1)
    • The A/C compressor cutoff switch (5), if equipped
    • The throttle position (TP) sensor (2)
    • The idle air control (IAC) motor (3)

    Object Number: 346148 Size: SH
  23. Connect the vacuum hose from the vacuum tank to the intake manifold.
  24. Install the power brake booster vacuum hose to the intake manifold.
  25. Install the cruise control cable, if equipped to the throttle shaft and the bracket. Refer to Cruise Control Cable Replacement in Cruise Control.

    26. Object Number: 325556 Size: SH
  26. Install the accelerator cable onto the throttle body.

    27. Object Number: 616716 Size: SH
  27. Wrap the cable in between the finger of the hook tab and the pulley wall. Make sure that the cable is fully seated in the pulley groove. The cable must not lie outside of the hook tab.

    28. Object Number: 616725 Size: SH
  28. Install the accelerator cable to the accelerator cable control bracket.

    29. Object Number: 616709 Size: SH
  29. Install the accelerator cable to the cable routing bracket.

    30. Notice: 

       • Handle the MAF sensor carefully.
       • Do not drop the MAF sensor in order to prevent damage to the MAF sensor.
       • Do not damage the screen located on the air inlet end of the MAF.
       • Do not touch the sensing elements.
       • Do not allow solvents and lubricants to come in contact with the sensing elements.
       • Use a small amount of a soap based solution in order to aid in the installation.


    Object Number: 424556 Size: SH
  30. Install air cleaner outlet duct to throttle body.
  31. Install air cleaner outlet duct to MAF sensor.

    32. Tighten
    Tighten the hose clamp to 4 N·m (32 lb in).


    Object Number: 10940 Size: SH
  32. Connect the IAT sensor harness connector.

    33. Object Number: 312278 Size: SH
  33. Install the air cleaner outlet duct retaining wingnut.

    34. Tighten
    Tighten the wingnut to 2 N·m (18 lb in).


    Object Number: 444792 Size: SH
  34. Connect the breather tube to the air cleaner outlet duct.