GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 1999 🢒 Intrigue 🢒 Engine 🢒 Engine Mechanical - 3.5L 🢒 Intake Manifold Replacement

Removal Procedure
  1. Disconnect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  2. Carefully disconnect the throttle body air inlet duct from the throttle body. Refer to Air Cleaner Inlet Duct Replacement in Engine Controls - 3.5L.
  3. Partially drain the engine coolant from the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.

    4. Object Number: 289500 Size: SH
  4. Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement .
  5. Disconnect the accelerator and cruise control cables from the throttle body and accelerator cable bracket. Refer to Accelerator Control Cable Replacement in Engine Controls - 3.5L.
  6. Disconnect the throttle body coolant hoses from the throttle body. Refer to Throttle Body Heater Inlet Hose Replacement and Throttle Body Heater Outlet Hose Replacement in Engine Cooling.

    7. Object Number: 293967 Size: SH
  7. Disconnect the fuel lines from the throttle body. Refer to Fuel Pressure Relief and Quick Connect Fitting Service in Engine Controls - 3.5L.

    8. Object Number: 293966 Size: SH
  8. Disconnect the fuel vapor line from the EVAP canister purge solenoid. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement in Engine Controls - 3.5L.

    9. Object Number: 293968 Size: SH
  9. Disconnect the brake booster vacuum hose from the brake booster. Refer to Vacuum Brake Booster Hose Replacement in Hydraulic Brakes.

    10. Object Number: 293970 Size: SH
  10. Disconnect the A/C vacuum hose from the intake manifold.
  11. Disconnect the surge tank inlet pipe retainer from the fuel injector rail.
  12. Disconnect the fuel injector wiring harness connectors. Refer to Engine Controls Component Views in Engine Controls - 3.5L.
  13. Disconnect the engine wiring harness connectors from the following components:

    14. Refer to Engine Controls Component Views in Engine Controls - 3.5L.

    • Throttle position (TP) sensor
    • Idle air control (IAC) valve
    • EVAP canister purge solenoid
    • Manifold absolute pressure (MAP) sensor
  14. Remove the engine wiring harness channel bolts from the camshaft covers. Refer to Engine Controls Component Views in Engine Controls - 3.5L.
  15. Remove and set aside the engine wiring harness and channel. Refer to Engine Controls Component Views in Engine Controls - 3.5L.

    16. Object Number: 235254 Size: SH
  16. Disconnect the fuel pressure regulator vacuum tube (1) from the regulator (2) and the throttle body (3).

    17. Object Number: 233873 Size: SH
  17. Disconnect and remove the PCV valve and both feed tubes (1, 2) from the camshaft covers and intake manifold.

    18. Object Number: 234130 Size: SH
  18. Remove the EGR valve outlet pipe retaining bolts from the intake manifold (1) and the water crossover (2).
  19. Remove the EGR valve outlet pipe (3).

    20. Object Number: 234312 Size: SH
  20. Disconnect the four fuel rail snap-lock retainers by pushing toward the camshaft covers and lifting.
  21. Remove the fuel rail (1) and fuel injectors (2) as an assembly and store in a clean, secure location away from any heat sources.

    22. Object Number: 483137 Size: SH
  22. Remove the throttle body heater hose insulator (2).

    23. Object Number: 520848 Size: SH
  23. Remove the intake manifold bolts.

    24. Object Number: 287926 Size: SH
  24. Disconnect the throttle body coolant hose from the water crossover feed tube (1).

    25. Object Number: 520849 Size: SH

    Notice: It is important to correctly identify the source of an oil leak. A power steering fluid leak or spillage can travel across the valley area of the engine and run out the weep hole, which is located at the back of the block. Failure to correctly identify the source of an oil leak can lead to the incorrect or unnecessary replacement of components.

  25. Remove the intake manifold.

    26. Important: If you are NOT replacing the intake manifold skip the following steps.

  26. If necessary, disassemble the intake manifold. Refer to Intake Manifold Disassemble .
  27. Clean and inspect the intake manifold. Refer to Intake Manifold Cleaning and Inspection .

Installation Procedure

    Object Number: 520849 Size: SH

    Important: If you did NOT replace the intake manifold skip the intake manifold assembly.

  1. If necessary, assemble the intake manifold. Refer to Intake Manifold Assemble .
  2. Install the intake manifold.

    3. Object Number: 287926 Size: SH
  3. Connect the throttle body heater hose to the water crossover feed tube (1).
  4. Install the hose clamp.

    5. Object Number: 520848 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.

    Important: Tighten the intake manifold bolts in circular pattern starting from the center and moving outward.

  5. Install the intake manifold bolts.

    6. Tighten
    Tighten the intake manifold bolts to 7 N·m (62 lb in).


    Object Number: 483137 Size: SH
  6. Install the throttle body heater hose insulator (2).

    7. Object Number: 234312 Size: SH
  7. Inspect the fuel injector O-rings (2) for misalignment or damage. Replace the O-rings if necessary.
  8. Install the fuel rail (1) and fuel injectors (2) by aligning the fuel injectors with their respective ports and pressing the four fuel rail snap-lock connectors into the intake manifold until they lock in place. DO NOT apply excessive pressure to the fuel rail in place. The need for excessive pressure may be caused by misalignment of a fuel injector and could cause damage to the seal or intake manifold.

    9. Object Number: 234130 Size: SH
  9. Install a new EGR outlet pipe (3).
  10. Install the EGR outlet pipe to intake manifold bolt (1).

    11. Tighten
    Tighten the EGR outlet pipe to intake manifold bolt to 10 N·m (89 lb in).

  11. Install the EGR outlet pipe to water crossover bolt (2).

    12. Tighten
    Tighten the EGR outlet pipe to water crossover bolt to 24 N·m (18 lb ft).


    Object Number: 233873 Size: SH
  12. Install the PCV valve and connect both feed tubes (1, 2) to the camshaft covers and intake manifold.

    13. Object Number: 293968 Size: SH
  13. Connect the brake booster vacuum hose to the brake booster. Refer to Vacuum Brake Booster Hose Replacement in Hydraulic Brakes.

    14. Object Number: 235254 Size: SH
  14. Connect the fuel pressure regulator vacuum tube (1) to the regulator (2) and the throttle body (3).

    15. Object Number: 293970 Size: SH
  15. Connect the A/C vacuum hose to the intake manifold.
  16. Install the engine wiring harness and channel. Refer to Engine Controls Component Views in Engine Controls - 3.5L.
  17. Install the engine wiring harness channel bolts to the camshaft covers. Refer to Engine Controls Component Views in Engine Controls - 3.5L.

    18. Tighten
    Tighten the engine wiring harness channel bolts to 10 N·m (89 lb in).

  18. Connect the surge tank inlet pipe retainer to the fuel injector rail.
  19. Connect the engine wiring harness connectors to the following components:

    20. Refer to Engine Controls Component Views in Engine Controls - 3.5L.

    • Throttle position (TP) sensor
    • Idle air control (IAC) valve
    • EVAP canister purge solenoid
    • Manifold absolute pressure (MAP) sensor
  20. Connect the fuel injector wiring harness connectors. Refer to Engine Controls Component Views in Engine Controls - 3.5L.
  21. Connect the throttle body coolant hoses to the throttle body. Refer to Throttle Body Heater Inlet Hose Replacement and Throttle Body Heater Outlet Hose Replacement in Engine Cooling.
  22. Connect the accelerator and cruise control cables to the throttle body and accelerator cable bracket. Refer to Accelerator Control Cable Replacement in Engine Controls - 3.5L.

    23. Object Number: 293967 Size: SH
  23. Connect the fuel lines to the throttle body. Refer to Quick Connect Fitting Service in Engine Controls - 3.5L.

    24. Object Number: 293966 Size: SH
  24. Connect the fuel vapor line to the EVAP canister purge solenoid. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement in Engine Controls - 3.5L.

    25. Object Number: 277027 Size: SH
  25. Install the fuel injector sight shield (3). Refer to Fuel Injector Sight Shield Replacement .
  26. Carefully connect the throttle body air inlet duct to the throttle body. Refer to Air Cleaner Inlet Duct Replacement in Engine Controls - 3.5L.
  27. Fill the cooling system with engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
  28. Connect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.