GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


Object Number: 21129  Size: SH
  1. Drain coolant. Refer to Cooling and Radiator.
  2. Remove the air inlet duct.
  3. Remove the accelerator and cruise control cables at the throttle body.
  4. Remove the accelerator control cable bracket.
  5. Remove the vacuum lines, noting position of hoses.
  6. Remove the electrical connectors at the IAC valve, MAF, MAP, and TP sensors.
  7. Remove the throttle body from the upper intake manifold. Refer to Throttle Body Assembly Replacement
  8. Remove the EGR valve.
  9. Remove the brake booster vacuum line.
  10. Remove the ignition coil wires numbers 2, 4, and 6 from the front three spark plugs.
  11. Remove the ignition coil wires from the wire retainers on top of the upper intake manifold and set wires aside.
  12. Remove the ignition coil assembly front bolt.
  13. Loosen ignition coil assembly rear nuts.
  14. Remove the MAP sensor and bracket.
  15. Remove the alternator braces.
  16. Remove the upper intake manifold bolts and studs.
  17. Remove the upper intake manifold and gaskets.

Installation Procedure


Object Number: 21129  Size: SH

Notice: Do not use solvent of any type when cleaning the gasket surfaces on the intake manifold and the throttle body assembly, as damage to the gasket surfaces and throttle body assembly may result.

Use care in cleaning the gasket surfaces on the intake manifold and the throttle body assembly, as sharp tools may damage the gasket surfaces.

  1. Clean the gasket sealing surfaces.
  2. Install the new upper intake manifold gaskets.
  3. Install the upper intake manifold.
  4. Install the upper intake manifold bolts and studs.
  5. Tighten
    Tighten the upper intake manifold bolts and studs to 25 N·m (18 lb ft)

    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 alternator braces.
  7. Install the MAP sensor and bracket.
  8. Install the ignition coil assembly front bolts.
  9. Tighten the ignition coil assembly rear nuts.
  10. Install the ignition coil wires to the wire retainers on top of the upper intake manifold.
  11. Install the ignition coil wires numbers 2, 4, and 6 from the front three spark plugs.
  12. Install the brake booster vacuum line.
  13. Install the EGR valve.
  14. Install the throttle body to the upper intake manifold. Refer to Throttle Body Assembly Replacement .
  15. Install the vacuum lines as noted during disassembly.
  16. Install the electrical connectors at IAC valve, MAF, MAP, and TP sensors.
  17. Install the accelerator control cable bracket.
  18. Install the accelerator and cruise control cables at the throttle body.
  19. Install the air inlet duct.
  20. Refill coolant. Refer to Cooling and Radiator.