GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2001 🢒 Grand Prix 🢒 Engine 🢒 Engine Mechanical - 3.1L 🢒 Upper Intake Manifold Replacement

Removal Procedure
  1. Disconnect the battery ground (negative) cable. Refer to Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  2. Disconnect the vacuum hose connection from the throttle body air inlet duct.
  3. Disconnect the wiring harness connection from the intake air temperature (IAT) sensor in the throttle body air inlet duct. Refer to Intake Air Temperature Sensor Replacement in Engine Controls - 3.1L.
  4. Remove the throttle body air inlet duct.
  5. Drain the engine coolant from the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  6. Remove the accelerator control and cruise control cables with bracket from the throttle body. Refer to Accelerator Control Cable Replacement in Engine Controls - 3.1L.
  7. Disconnect the wiring harness connectors from the throttle body.
    8. • Throttle position (TP) sensor
    • Idle air control (IAC) valve
  8. Disconnect the (left) front spark plug wires. Refer to Spark Plug Wire Replacement in Engine Controls - 3.1L.
  9. Disconnect the wiring harness attachment clips.
    10. • Camshaft position (CMP) sensor wiring harness
    • Left spark plug wire harness
    • Engine wiring harness
  10. Disconnect the thermostat bypass pipe coolant hoses from the throttle body.
  11. Remove the ignition coil bracket with the coils, the purge solenoid and the vacuum canister solenoid. Refer to Ignition Coil Replacement and Evaporative Emission Canister Purge Solenoid Valve Replacement in Engine Controls - 3.1L.

    12. Object Number: 248103 Size: SH
  12. Disconnect the vacuum hose at the manifold air pressure (MAP) sensor and upper intake manifold.
  13. Remove the manifold air pressure (MAP) sensor and the bracket. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls - 3.1L.

    14. Object Number: 248101 Size: SH
  14. Disconnect the emission control vacuum harness.
  15. Disconnect the vacuum hose connections from the upper intake manifold.
    16. • Vacuum booster hose
    • Automatic transaxle vacuum modulator hose
    • Heater and air conditioning vacuum source hose
    • Fuel pressure regulator
  16. Remove the generator brace. Refer to Generator Brace Replacement in Engine Electrical.

    17. Object Number: 61828 Size: MH
  17. Remove the exhaust gas recirculation (EGR) valve. Refer to Exhaust Gas Recirculation Valve Replacement in Engine Controls - 3.1L.

    18. Object Number: 190509 Size: SH
  18. Remove the right upper intake manifold bolts and studs.

    19. Object Number: 325936 Size: SH
  19. Remove the left upper intake manifold bolts.
  20. Remove the upper intake manifold.

    21. Object Number: 96379 Size: SH
  21. Remove the upper intake manifold gasket.

    22. Object Number: 61827 Size: SH
  22. If replacing the upper intake manifold, remove the throttle body. Refer to Throttle Body Assembly Replacement in Engine Controls - 3.1L.
  23. Clean the seal surfaces on the manifold with degreaser.

Installation Procedure

    Object Number: 61827 Size: SH
  1. If removed, install the throttle body. Refer to Throttle Body Assembly Replacement in Engine Controls - 3.1L.

    2. Object Number: 96379 Size: SH
  2. Install the upper intake manifold gasket.

    3. Object Number: 325936 Size: SH
  3. Install the upper intake manifold.
  4. Loosely install the left upper intake manifold bolts.

    5. Object Number: 190509 Size: SH
  5. Loosely install the right upper intake manifold bolts and studs.

    6. 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.

  6. Install the upper intake manifold bolts and studs.

    7. Tighten
    Tighten the upper intake manifold bolts and studs to 25 N·m (18 lb ft).


    Object Number: 61828 Size: MH
  7. Install the exhaust gas recirculation (EGR) valve. Refer to Exhaust Gas Recirculation Valve Replacement in Engine Controls - 3.1L.
  8. Install the generator brace. Refer to Generator Brace Replacement in Engine Electrical.
  9. Connect the vacuum hose connections to the upper intake manifold.
    10. • Vacuum booster hose
    • Automatic transaxle vacuum modulator hose
    • Heater and air conditioning vacuum source hose
    • Fuel pressure regulator

    Object Number: 248101 Size: SH
  10. Connect the emission control vacuum harness.
  11. Install the manifold air pressure (MAP) sensor and bracket. Refer to Manifold Absolute Pressure Sensor Replacement in Engine Controls - 3.1L.

    12. Object Number: 248103 Size: SH
  12. Connect the vacuum hose at the manifold air pressure (MAP) sensor and the upper intake manifold.
  13. Install the ignition coil bracket with the coils, the purge solenoid and the vacuum canister solenoid. Refer to Ignition Coil Replacement and Evaporative Emission Canister Purge Solenoid Valve Replacement in Engine Controls - 3.1L.
  14. Connect the thermostat bypass pipe coolant hoses to the throttle body.
  15. Connect the wiring harness attachment clips.
    16. • Camshaft position (CMP) sensor wiring harness
    • left spark plug wire harness
    • Engine wiring harness
  16. Connect the left spark plug wires. Refer to Spark Plug Wire Replacement in Engine Controls - 3.1L.
  17. Connect the wiring harness connectors to the throttle body.
    18. • Throttle position (TP) sensor
    • Idle air control (IAC) valve
  18. Install the accelerator control and cruise control cables with bracket to the throttle body. Refer to Accelerator Control Cable Replacement in Engine Controls - 3.1L.
  19. Fill the cooling system with engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
  20. Install the throttle body air inlet duct.
  21. Connect the wiring harness connection to the intake air temperature (IAT) sensor in the throttle body air inlet duct. Refer to Intake Air Temperature Sensor Replacement in Engine Controls - 3.1L.
  22. Connect the vacuum hose connection to the throttle body air inlet duct.
  23. Connect the battery ground (negative) cable. Refer to Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.