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For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC K Sierra - 4WD 🢒 Engine 🢒 Engine Electrical 🢒 Intake Manifold Replacement

Intake Manifold Replacement Upper

Removal Procedure
  1. Disconnect the PCV hose from the air cleaner outlet duct.
  2. Remove the air cleaner outlet duct from the throttle body and the air cleaner assembly. Refer to Air Cleaner Outlet Duct Replacement in Engine Controls.

    3. Object Number: 491821 Size: SH
  3. Disconnect the following electrical connectors:
    4. • 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
  4. Disconnect the following electrical connectors:
    5. • 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
  5. Disconnect the following electrical connectors:
    6. • The manifold absolute pressure (MAP) sensor (2)
    • The EVAP canister purge solenoid valve (1)

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

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

    10. Object Number: 310243 Size: SH
  10. Remove the nut holding the engine wiring harness bracket to the stud at the EVAP canister purge solenoid valve.
  11. Remove the nut and the ground wire from the engine wiring harness bracket stud at the rear of the right cylinder head.
  12. Remove the stud holding the engine wiring harness bracket.
  13. Move the engine wiring harness and engine wiring harness brackets aside.
  14. Remove the EVAP canister purge solenoid valve. Refer to EVAP Canister Purge Solenoid Valve Replacement in Engine Controls.

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

    16. Object Number: 346148 Size: SH
  16. Disconnect the vacuum brake booster hose from the intake manifold.
  17. Disconnect the accelerator control cable from the throttle shaft and the accelerator control cable bracket on the side of the throttle body. Refer to Accelerator Control Cable Replacement in Engine Controls.
  18. Disconnect the cruise control cable, if equipped from the throttle shaft and the accelerator control cable bracket on the side of the throttle body. Refer to Cruise Control Cable Replacement in Cruise Control.

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

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

    24. Object Number: 334513 Size: SH
  24. Remove the upper intake manifold. Refer to Intake Manifold Disassemble .
  25. Clean all sealing surfaces and the upper intake manifold. Refer to Intake Manifold Clean and Inspect .

Installation Procedure

    Object Number: 334513 Size: SH
  1. Install the upper intake manifold.

    2. Refer to Intake Manifold Assemble .

  2. Install the fuel lines to the fuel meter body assembly. Refer to Fuel Hose/Pipes Replacement - Engine Compartment in Engine Controls.

    3. Object Number: 398033 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.

  3. Install the accelerator control cable bracket to the throttle body and the intake manifold.

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


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

    5. Tighten
    Tighten the cable bracket nuts to 10 N·m (88 lb in).

  5. Install the engine wiring harness clip to the accelerator control cable bracket.
  6. 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.
  7. Install the accelerator control cable to the throttle shaft and the accelerator control cable bracket. Refer to Accelerator Control Cable Replacement in Engine Controls.

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

    9. Object Number: 346148 Size: SH
  9. Connect the vacuum brake booster hose to the intake manifold.
  10. Install the EVAP canister purge solenoid valve. Refer to EVAP Canister Purge Solenoid Valve Replacement in Engine Controls.

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

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

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

    14. Tighten
    Tighten the engine wiring harness bracket nut to 10 N·m (88 lb in).

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

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


    Object Number: 310241 Size: SH
  15. Install the engine wiring harness bracket on the upper intake studs.
  16. Install the engine wiring harness bracket nuts.

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


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

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

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

    Object Number: 398868 Size: SH
  20. Connect the AIR crossover pipe to the AIR pipe assemblies.
  21. Install the air cleaner outlet duct to the throttle body and the air cleaner assembly. Refer to Air Cleaner Outlet Duct Replacement in Engine Controls.
  22. Connect the PCV hose to the air cleaner outlet duct.

Intake Manifold Replacement Lower

Removal Procedure
  1. Disconnect the battery negative cable. Refer to Battery Cable Replacement in Engine Electrical.
  2. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  3. Disconnect the PCV hose from the air cleaner outlet duct.
  4. Remove the air cleaner outlet duct from the throttle body and the air cleaner assembly. Refer to Air Cleaner Outlet Duct Replacement in Engine Controls.
  5. Remove the accelerator cable from the throttle shaft and the accelerator control cable bracket at the side of the throttle body. Refer to Accelerator Control Cable Replacement in Engine Controls.
  6. Disconnect the cruise control cable, if equipped from the throttle shaft and the accelerator control cable bracket at the side of the throttle body. Refer to Cruise Control Cable Replacement in Cruise Control.

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

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

    12. Object Number: 491821 Size: SH
  12. Disconnect the following electrical connectors:
    13. • The A/C pressure switch (4), if equipped
    • The A/C compressor clutch (1), if equipped
    • The exhaust gas recirculation (EGR) valve (2)
    • The generator battery positive cable (3)

    Object Number: 491817 Size: SH
  13. Disconnect the following electrical connectors:
    14. • The fuel meter body assembly (3)
    • The idle air control (IAC) motor (2)
    • The throttle position (TP) sensor (1)
    • The engine coolant temperature (ECT) sensor (4)

    Object Number: 491816 Size: SH
  14. Disconnect the following electrical connectors:
    15. • The EVAP canister purge solenoid valve (1)
    • The manifold absolute pressure (MAP) sensor (2)
    • The ignition control module (ICM) (4)
    • The ignition coil (3)

    Object Number: 310243 Size: SH
  15. Remove the nut holding the engine wiring harness bracket to the EVAP purge solenoid valve stud.
  16. Remove the nut holding the ground wire to the engine wiring harness bracket stud at the rear of the right cylinder head.
  17. Remove the stud holding the engine wiring harness bracket.

    18. Object Number: 310241 Size: SH
  18. Remove the two nuts holding the engine wiring harness bracket to the upper intake manifolds studs.
  19. Remove the engine wiring harness bracket from the studs.
  20. Move the engine wiring harness with the brackets aside.

    21. Object Number: 182853 Size: SH
  21. Remove the radiator inlet hose at the water outlet. Refer to Radiator Inlet Hose Replacement in Engine Cooling. .
  22. Remove the water pump inlet hose from the intake manifold.

    23. Object Number: 316440 Size: SH
  23. Remove the bolt holding the bracket for the heater hose tube from the generator bracket.
  24. Remove the heater hoses from the engine. Refer to Heater Hoses Replacement in Heating and Ventilation (Non-A/C).
  25. Remove the distributor. Refer to Distributor Replacement in Engine Electrical.
  26. Disconnect the fuel supply and return pipes at the rear of the intake manifold. Refer to Fuel Hose/Pipes Replacement - Engine Compartment in Engine Controls.

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

    28. Object Number: 346148 Size: SH
  28. Disconnect the vacuum brake booster hose from the intake manifold.
  29. Disconnect the hose to the EVAP canister purge solenoid valve. Refer to EVAP Canister Purge Solenoid Valve Replacement in Engine Controls.

    30. Object Number: 172982 Size: SH
  30. Remove the spark plug wire harness retainer from the exhaust gas recirculation (EGR) valve inlet pipe.
  31. Remove the clamp bolt for the EGR valve inlet pipe.
  32. Remove the EGR valve inlet pipe from the intake manifold and the exhaust manifold.

    33. Object Number: 340090 Size: SH
  33. In order to remove the front intake manifold bolt, perform the following:
    34. 33.1. Remove the drive belt. Refer to Drive Belt Replacement .
    33.2. Loosen the power steering pump rear bracket side nut.
    33.3. Remove the power steering pump rear bracket front nut.
    33.4. Remove the bolts and the nut for the power steering pump mounting bracket.
    33.5. Leave the A/C compressor, if equipped, and the power steering pump on the bracket.
    33.6. Slide the power steering pump mounting bracket forward to access the bolt at the front of the intake manifold.

    Object Number: 31510 Size: SH
  34. Remove the lower intake manifold bolts.
  35. Remove the lower intake manifold. Refer to Intake Manifold Removal .
  36. Clean all sealing surfaces and the intake manifold. Refer to Intake Manifold Clean and Inspect .
  37. If the lower intake manifold requires replacement refer to Intake Manifold Disassemble and Intake Manifold Assemble .

Installation Procedure

    Object Number: 31510 Size: SH

    Notice: Proper lower intake manifold fastener tightening sequence and torque is critical. Always follow the tightening sequence, and torque the intake manifold bolts using the 3 step method. Failing to do so may distort the crankshaft bearing bore alignment and cause damage to the crankshaft bearings.

  1. Install the lower intake manifold. Refer to Intake Manifold Installation .

    2. Object Number: 340090 Size: SH
  2. Position the power steering pump mounting bracket.
  3. Install the three bolts and the nut.

    4. 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. Install the front nut for the power steering pump rear bracket.

    5. Tighten
    Tighten the power steering pump mounting bracket bolts, the nut, and the power steering pump rear bracket nuts to 41 N·m (30 lb ft).

  5. Install the drive belt. Refer to Drive Belt Replacement .

    6. Object Number: 172982 Size: SH
  6. Install the EGR valve inlet pipe to the intake manifold and the exhaust manifold.

    7. Tighten

    1. Tighten the EGR valve inlet pipe intake manifold nut to 25 N·m (18 lb ft).
    2. Tighten the EGR valve inlet pipe exhaust manifold nut to 30 N·m (22 lb ft).
    3. Tighten the EGR valve inlet pipe clamp bolt 25 N·m (18 lb ft).
  7. Install the spark plug wire harness retainer on the EGR valve inlet pipe.

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

    9. Object Number: 346148 Size: SH
  9. Install the vacuum brake booster hose to the intake manifold.
  10. Install the EVAP canister purge solenoid valve hose. Refer to EVAP Canister Purge Solenoid Valve Replacement in Engine Controls.
  11. Install the fuel supply and return pipes to the rear of the intake manifold. Refer to Fuel Hose/Pipes Replacement - Engine Compartment in Engine Controls.

    12. Object Number: 334551 Size: SH

    Important: In order to install the distributor for the correct engine timing, position the engine to number one cylinder top dead center.

  12. Remove the spark plug for number one cylinder.
  13. Rotate the crankshaft until number one cylinder is in the compression stroke.
  14. Align the two reference marks on the crankshaft balancer (1) and (4) with the two alignment marks (2) and (3) on the front cover.
  15. Install the spark plug. Refer to Spark Plug Replacement in Engine Electrical.
  16. Install the distributor. Refer to Distributor Replacement in Engine Electrical.

    17. Object Number: 316440 Size: SH
  17. Install the water pump inlet hose to the intake manifold.
  18. Install the heater hoses to the engine. Refer to Heater Hoses Replacement in Heating and Ventilation (Non-A/C).
  19. Install the bolt holding the bracket for the heater hose tube to the generator bracket.

    20. Tighten
    Tighten the bolt to 25 N·m (18 lb ft).

  20. Install the radiator inlet hose to the water outlet. Refer to Radiator Inlet Hose Replacement in Engine Cooling.
  21. Refill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.

    22. Object Number: 310243 Size: SH
  22. Position the engine wiring harness and the engine wiring harness brackets.
  23. Install the stud at the rear of the right cylinder head for the engine wiring harness bracket.

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

  24. Install the nut holding the engine wiring harness bracket to the EVAP purge canister solenoid stud.

    25. Tighten
    Tighten the engine wiring harness bracket nut to 10 N·m (88 lb in).

  25. Install the nut holding the ground wire to the stud at the rear of the cylinder head.

    26. Tighten
    Tighten the nut to 16 N·m (12 lb ft).


    Object Number: 310241 Size: SH
  26. Install the nuts holding the engine wiring harness bracket to the upper intake manifold studs.

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


    Object Number: 491816 Size: SH
  27. Connect the following electrical connectors:
    28. • The EVAP canister purge solenoid valve (1)
    • The manifold absolute pressure (MAP) sensor (2)
    • The ignition control module (ICM) (4)
    • The ignition coil (3)

    Object Number: 491817 Size: SH
  28. Connect the following electrical connectors:
    29. • The fuel meter body assembly (3)
    • The idle air control (IAC) motor (2)
    • The throttle position (TP) sensor (1)
    • The engine coolant temperature (ECT) sensor (4)

    Object Number: 491821 Size: SH
  29. Connect the following electrical connectors:
    30. • The A/C pressure switch (4), if equipped
    • The A/C compressor clutch (1), if equipped
    • The exhaust gas recirculation (EGR) valve (2)
    • The generator battery positive cable (3)

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

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

    32. Tighten
    Tighten the accelerator control cable bracket nuts to 10 N·m (88 lb in).

  32. Install the accelerator cable to the throttle shaft and the accelerator control cable bracket. Refer to Accelerator Control Cable Replacement in Engine Controls.
  33. 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.
  34. Install the engine wiring harness and clip to the accelerator control cable bracket.
  35. Install the air cleaner outlet duct to the throttle body and the air cleaner assembly. Refer to Air Cleaner Outlet Duct Replacement in Engine Controls.
  36. Connect the PCV hose to the air cleaner outlet duct.
  37. Connect the battery negative cable. Refer to Battery Cable Replacement in Engine Electrical.