GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 742280  Size: SH
  1. Remove the oil level indicator tube. Refer to Oil Level Indicator and Tube Replacement in Engine Mechanical - 8.1L.
  2. Raise and suitably support the vehicle with safety stands. Refer to Lifting and Jacking the Vehicle in General Information.
  3. Remove the exhaust manifold pipe nuts.
  4. Remove the exhaust manifold seal.
  5. Allow the muffler pipe to hang.
  6. Lower the vehicle.

  7. Object Number: 470666  Size: SH

    Important: Twist the spark plug boot one-half turn in order the release the boot. Pull on the spark plug boot only. Do not pull on the spark plug wire or the wire could be damaged.

  8. Remove the spark plug wires from the spark plugs and ignition coils.
  9. Remove the spark plugs. Refer to Spark Plug Replacement in Engine Controls - 8.1L.

  10. Object Number: 470678  Size: SH
  11. Remove the exhaust manifold heat shield nuts.
  12. Remove the heat shield.

  13. Object Number: 470686  Size: SH
  14. Remove the exhaust manifold bolt and nuts.
  15. Remove the exhaust manifold and gasket. Discard the gasket.
  16. Clean and inspect the exhaust manifold. Refer to Exhaust Manifold Cleaning and Inspection in the Engine Mechanical-8.1L Unit Repair.

Installation Procedure


    Object Number: 470686  Size: SH
  1. Install a NEW gasket.
  2. Install the exhaust manifold.
  3. 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 exhaust manifold bolts and nut.
  5. Tighten

        • Tighten the exhaust manifold bolt to 35 N·m (26 lb ft).
        • Tighten the exhaust manifold nuts to 16 N·m (12 lb ft).
  6. Raise the vehicle.

  7. Object Number: 470678  Size: SH
  8. Install the exhaust manifold heat shield.
  9. Install the exhaust manifold heat shield nuts.
  10. Tighten
    Tighten the exhaust manifold heat shield nuts to 25 N·m (18 lb ft).

  11. Install the spark plugs. Refer to Spark Plug Replacement in Engine Controls - 8.1L.

  12. Object Number: 470666  Size: SH

    Important: Fully install the spark plug wire by pushing on the exposed end of the spark plug boot. Do not push the spark plug wire on the spark plug by using the metal heat shield.

  13. Install the spark plug wires to the spark plugs and ignition coils.

  14. Object Number: 742280  Size: SH
  15. Raise and suitably support the vehicle with safety stands.
  16. Raise the muffler pipe up to the manifold.
  17. Install the exhaust pipe seal.
  18. Install the exhaust manifold pipe nuts.
  19. Tighten
    Tighten the exhaust manifold pipe nuts to 50 N·m (37 lb ft).

  20. Lower the vehicle.