GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2001 🢒 Grand Prix 🢒 General Information 🢒 General Information 🢒 Lower Intake Manifold Replacement

Removal Procedure
  1. Disconnect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  2. Remove the upper intake manifold. Refer to Upper Intake Manifold Replacement .
  3. Remove the left valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement - Left Side .
  4. Remove the right valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement - Right Side .

    5. Object Number: 190517 Size: SH
  5. Disconnect the engine coolant temperature (ECT) wiring harness.

    6. Object Number: 190518 Size: SH
  6. Disconnect and remove the fuel injector and manifold air pressure (MAP) wiring harness.

    7. Object Number: 190512 Size: SH
  7. Remove the fuel pipe clip bolt.

    8. Object Number: 190511 Size: SH
  8. Remove the fuel pipe clip.

    9. Object Number: 190514 Size: SH
  9. Disconnect the fuel feed pipe from the fuel injector rail. Refer to Fuel Hose/Pipes Replacement - Filter to Engine in Engine Controls - 3.1L.

    10. Object Number: 190513 Size: SH
  10. Disconnect the fuel return pipe from the fuel injector rail. Refer to Fuel Hose/Pipes Replacement - Filter to Engine in Engine Controls - 3.1L.

    11. Object Number: 190516 Size: SH
  11. Remove the fuel injector rail. Refer to Fuel Injection Fuel Rail Assembly Replacement in Engine Controls - 3.1L.
  12. Remove the power steering pump from the front engine cover and reposition. Refer to Power Steering Pump Replacement in Power Steering System.

    13. Object Number: 190515 Size: SH
  13. Disconnect the heater inlet pipe with heater hose from the lower intake manifold and reposition.
  14. Disconnect the radiator inlet hose from the engine. Refer to Radiator Inlet Hose Replacement in Engine Cooling.

    15. Object Number: 190522 Size: SH
  15. Disconnect the thermostat bypass hose from the thermostat bypass pipe and lower intake manifold pipe.

    16. Object Number: 54281 Size: SH
  16. Remove the lower intake manifold bolts and DISCARD the bolts.
  17. Remove the lower intake manifold.
  18. Remove the valve rocker arms and pushrods. Refer to Valve Rocker Arm and Push Rod Replacement .

    19. Object Number: 61820 Size: SH
  19. Remove the lower intake manifold gaskets and seals.
  20. Clean the lower intake manifold gasket and seal surfaces on the cylinder heads and the engine block.
  21. Clean the gasket and seal surfaces on the lower intake manifold with degreaser.
  22. Remove all the loose RTV sealer.

    23. Object Number: 190519 Size: SH
  23. Remove the engine coolant temperature (ECT) sensor.

    24. Object Number: 190520 Size: SH
  24. Remove the water outlet bolts.
  25. Remove the water outlet.

    26. Object Number: 190521 Size: SH
  26. Remove the thermostat. Refer to Engine Coolant Thermostat Replacement in Engine Cooling.

Installation Procedure

    Object Number: 190521 Size: SH
  1. Install the thermostat. Refer to Engine Coolant Thermostat Replacement in Engine Cooling.

    2. Object Number: 190520 Size: SH
  2. Install the water outlet.

    3. Notice: Refer to Fastener Notice in the Preface section.

  3. Install the water outlet bolts.

    4. Tighten
    Tighten the water outlet bolts to 25 N·m (18 lb ft).


    Object Number: 190519 Size: SH
  4. Install the engine coolant temperature (ECT) sensor.

    5. Tighten
    Tighten the engine coolant temperature (ECT) sensor to 23 N·m (17 lb ft).


    Object Number: 843417 Size: SH

    Important: All gasket-mating surfaces need to be free of oil, and foreign material. Use GM P/N 12346139 (Canadian P/N 10953463) or equivalent to clean surfaces.

  5. Install the lower intake manifold gaskets.
  6. With gaskets in place supply a small drop 8-10 mm (0.31-0.39 in) of RTV sealer GM P/N 12346141 (Canadian P/N 89022195) or equivalent to the 4 corners of the intake manifold to block joint (1).
  7. Connect the 2 small drops with a bead of RTV sealer that is between 8-10 mm (0.31-0.39 in) wide and 3.0-5.0 mm (0.12-0.20 in) thick (2).
  8. Install the valve rocker arms and pushrods. Refer to Valve Rocker Arm and Push Rod Replacement .
  9. Install the lower intake manifold.

    10. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 187067 Size: SH

    Important: All lower intake manifold bolts need to be cleaned and free of any foreign material, only new bolts are to be used.

    Important: Manufacturer recommends the center bolts be fully torqued before the diagonal bolts to assure proper seal ability.

    Important: Lower the intake manifold bolts in location 6 and 7 should be torqued to specification using a crows foot type tool.

  10. Install NEW intake manifold bolts.

    11. Tighten

    1. Tighten the lower intake manifold bolts in sequence to 7 N·m (62 lb in) on the first pass.
    2. Tighten the lower intake manifold bolts  (1,2,3,4) in sequence to 13 N·m (115 lb in) on the final pass.
    3. Tighten the lower intake manifold bolts  (5,6,7,8) in sequence to 25 N·m (18 lb in) on the final pass.

    Object Number: 190522 Size: SH
  11. Connect the thermostat bypass hose to the thermostat bypass pipe and lower intake manifold pipe.
  12. Connect the radiator inlet hose to the engine. Refer to Radiator Inlet Hose Replacement in Engine Cooling.

    13. Object Number: 190515 Size: SH
  13. Connect the heater inlet pipe and heater hose to the lower intake manifold.
  14. Install the power steering pump to the front engine cover. Refer to Power Steering Pump Replacement in Power Steering.

    15. Object Number: 862487 Size: SH

    Important: Do not press on the fuel pressure regulator valve when installing the fuel injector rail assembly.

  15. Install the fuel rail assembly.
    16. 15.1. Install the fuel injector O-rings using GM P/N 12345616 (Canadian P/N 993182) or equivalent.
    15.2. Install the injector nozzles into the lower intake manifold injector bores.
    15.3. Press on the injector rail using the palms of both hands until the injectors are fully seated.
  16. Install the injector bolts.

    17. Tighten
    Tighten the fuel injector rail bolts to 10 N·m (89 lb in).


    Object Number: 190513 Size: SH
  17. Connect the fuel return pipe to the fuel injector rail. Refer to Fuel Hose/Pipes Replacement - Filter to Engine in Engine Controls - 3.1L.

    18. Object Number: 190514 Size: SH
  18. Connect the fuel feed pipe to the fuel injector rail. Refer to Fuel Hose/Pipes Replacement - Filter to Engine in Engine Controls - 3.1L.

    19. Object Number: 190512 Size: SH
  19. Install the fuel pipe clip bolt.

    20. Tighten
    Tighten the fuel pipe clip bolt to 8 N·m (71 lb in).


    Object Number: 190518 Size: SH
  20. Install and connect the fuel injector and Manifold Air Pressure (MAP) wiring harness.

    21. Object Number: 190517 Size: SH
  21. Connect the Engine Coolant Temperature (ECT) wiring harness.
  22. Install the right valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement - Right Side .
  23. Install the left valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement - Left Side .
  24. Install the upper intake manifold. Refer to Upper Intake Manifold Replacement .
  25. Connect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.