GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 GMC C Sierra - 2WD 🢒 Engine 🢒 Engine Mechanical - 4.3L 🢒 Upper Intake Manifold Replacement

Removal Procedure

Important: It is not necessary to remove the upper intake manifold in order to remove the lower intake manifold.


    Object Number: 360851 Size: SH
  1. Separate the MAF/IAT sensor assembly and the air inlet tube by loosening the hose clamp.
  2. Disconnect the PCV hose from the air cleaner outlet duct.

    3. Object Number: 489179 Size: SH
  3. Remove the air inlet tube and resonator retaining wing nut.

    4. Object Number: 489176 Size: SH
  4. Remove the air inlet tube and resonator from the throttle body by pivoting the air inlet tube and resonator upward until the hinge clip releases from the lip on the throttle body.

    5. Object Number: 26764 Size: SH
  5. Remove the accelerator cable from the cable routing bracket.

    6. Object Number: 325556 Size: SH
  6. Remove the accelerator cable from the throttle body lever.
  7. Disconnect the cruise control cable, if equipped from the throttle shaft and the accelerator cable bracket at the side of the throttle body. Refer to Cruise Control Cable Replacement in Cruise Control.

    8. Object Number: 398030 Size: SH
  8. Remove the engine wiring harness clip from the accelerator control cable bracket.
  9. Remove the accelerator control cable bracket with the accelerator control cable and the cruise control cable from the throttle body.
  10. Move and secure the accelerator control cable and the cruise control cable out of the way.

    11. Object Number: 398868 Size: SH
  11. Disconnect the secondary air injection (AIR) crossover pipe from the AIR pipe assemblies, if equipped.
  12. Remove the AIR crossover pipe, if equipped.

    13. Object Number: 491821 Size: SH
  13. Disconnect the following electrical connections:
    14. • The A/C compressor clutch (1), if equipped
    • The A/C pressure switch (4), if equipped
    • The EGR valve (2)

    Object Number: 491817 Size: SH
  14. Disconnect the following electrical connections:
    15. • The throttle position (TP) sensor (1)
    • The idle air control (IAC) motor (2)
    • The fuel meter body assembly connector (3)

    Object Number: 491816 Size: SH
  15. Disconnect the following electrical connections:
    16. • The manifold absolute pressure (MAP) sensor (2)
    • The EVAP canister purge solenoid valve (1)

    Object Number: 310241 Size: SH
  16. Remove the two nuts holding the engine wiring harness bracket to the upper intake manifold studs.
  17. Remove the engine wiring harness bracket from the studs.

    18. Object Number: 310243 Size: SH
  18. Remove the nut holding the engine wiring harness bracket to the stud at the EVAP canister purge solenoid valve.
  19. Remove the nut and the ground wire from the engine wiring harness bracket stud at the rear of the right cylinder head.
  20. Remove the stud holding the engine wiring harness bracket.
  21. Move the engine wiring harness and the engine wiring harness brackets aside.
  22. Remove the EVAP canister purge solenoid valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement in Engine Controls - 4.3L.

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

    24. Object Number: 346148 Size: SH
  24. Disconnect the power brake booster vacuum hose from the intake manifold.

    25. Object Number: 398033 Size: SH
  25. Remove the accelerator control cable bracket from the intake manifold and the throttle body.
  26. Remove the fuel lines from the fuel meter body assembly. Refer to Fuel Hose/Pipes Replacement - Engine Compartment in Engine Controls - 4.3L.

    27. Object Number: 516794 Size: SH
  27. Remove the studs for the upper intake manifold.
  28. Remove the upper intake manifold.

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

    31. Object Number: 516773 Size: SH
  31. Remove the seal (O-ring) from the fuel meter body assembly.
  32. Discard the seal.

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

  33. Clean all sealing surfaces and the inside of the upper intake manifold with a shop towel and cleaning solvent.
  34. Inspect the upper intake manifold for the following:
    35. • Cracks or other damage to the exterior
    • Cracking or damage to the gasket grooves
    • Loose or damaged bolt hole thread inserts

    Object Number: 516797 Size: SH
  35. If replacing the upper intake manifold, turn and remove the power brake booster vacuum tube fitting from the upper intake manifold.
  36. Remove and discard the seal (O-ring).

    37. Object Number: 516804 Size: SH
  37. If replacing the upper intake manifold, turn and remove the PCV valve cover from the upper intake manifold.
  38. Remove and discard the seal (O-ring).
  39. Remove the throttle body if replacing the upper intake manifold. Refer to Throttle Body Assembly Replacement in Engine Controls - 4.3L.
  40. 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: 516804 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: 516797 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: 398033 Size: SH
  13. Install the accelerator control cable bracket to the throttle body and the intake manifold.

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


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

    15. Object Number: 346148 Size: SH
  15. Connect the power brake booster vacuum hose to the intake manifold.

    16. Object Number: 310243 Size: SH
  16. Position the engine wiring harness and engine wiring harness brackets.
  17. Install the stud holding the engine wiring harness bracket to the rear of the right cylinder head.

    18. Tighten
    Tighten the engine wiring harness bracket stud to 25 N·m (18 lb ft).

  18. Install the nut holding the engine wiring harness bracket to the stud at the EVAP canister purge solenoid valve.

    19. Tighten
    Tighten the engine wiring harness bracket nut to 9 N·m (80 lb in).

  19. Install the nut and the ground wire on the engine wiring harness bracket stud at the rear of the right cylinder head.

    20. Tighten
    Tighten the ground wire nut to 16 N·m (12 lb ft).


    Object Number: 310241 Size: SH
  20. Install the engine wiring harness bracket on the upper intake manifold studs.
  21. Install the engine wiring harness bracket nuts.

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


    Object Number: 491821 Size: SH
  22. Connect the following electrical connections:
    23. • The A/C compressor clutch (1), if equipped
    • The A/C pressure switch (4), if equipped
    • The EGR valve (2)

    Object Number: 491817 Size: SH
  23. Connect the following electrical connections:
    24. • The throttle position (TP) sensor (1)
    • The idle air control (IAC) motor (2)
    • The fuel meter body assembly connector (3)

    Object Number: 491816 Size: SH
  24. Connect the following electrical connections:
    25. • The manifold absolute pressure (MAP) sensor (2)
    • The EVAP canister purge solenoid valve (1)

    Object Number: 398030 Size: SH
  25. Install the accelerator control cable bracket with the accelerator control cable and the cruise control cable and the nuts to the throttle body.

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

  26. Install the engine wiring harness clip to the accelerator control cable bracket.
  27. Install the cruise control cable, if equipped to the throttle shaft and the accelerator control cable bracket. Refer to Cruise Control Cable Replacement in Cruise Control.

    28. Object Number: 325557 Size: MH
  28. Install the accelerator cable to the engine cable bracket.

    29. Object Number: 325556 Size: SH
  29. Install the accelerator cable to the throttle body lever.

    30. Object Number: 26764 Size: SH
  30. Install the accelerator cable to the cable routing bracket.

    31. Object Number: 398868 Size: SH
  31. Connect the AIR crossover pipe to the AIR pipe assemblies.

    32. Object Number: 489176 Size: SH
  32. Align the hinge clip with the lip on the throttle body.

    33. Install the air inlet tube and resonator to the throttle body by pivoting the air inlet tube and resonator downward until the mounting stud is through the hole in the air inlet tube.


    Object Number: 489179 Size: SH
  33. Install the resonator retaining wing nut.
  34. Connect the PCV hose to the air cleaner outlet duct.

    35. Object Number: 373468 Size: SH
  35. Connect the MAF/IAT sensor assembly harness connector.