GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 HUMMER 🢒 2008 🢒 H2 🢒 Engine 🢒 Engine Exhaust 🢒 Exhaust Manifold Replacement - Left Side

Removal Procedure

    Object Number: 664832 Size: SH
  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle .
  2. Remove the exhaust manifold pipe nuts.
  3. Lower the vehicle.
  4. Remove the spark plug wires. Refer to Spark Plug Wire Replacement .

    5. Object Number: 260074 Size: SH
  5. Remove the exhaust manifold bolts, manifold, and gasket.
  6. Discard the gasket.

    7. Object Number: 492766 Size: SH
  7. Remove the heat shield bolts (3), and shield (2) from the exhaust manifold (1), if necessary.

Installation Procedure

    Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 492766 Size: SH
  1. Install the heat shield (2), and bolts (3) to the exhaust manifold (1), if necessary.

    2. Tighten
    Tighten the bolts to 9 N·m (80 lb in).


    Object Number: 260074 Size: SH

    Important: 

       • Tighten the exhaust manifold bolts as specified in the service procedure. Improperly installed and/or leaking exhaust manifold gaskets may affect vehicle emissions and/or On-Board Diagnostics (OBD) II system performance.
       • The cylinder head exhaust manifold bolt hole threads must be clean and free of debris or threadlocking material.
       • Do not apply sealant to the first three threads of the bolt.

  2. Apply a 5 mm (0.2 in) wide band of threadlock GM P/N 12345493 (Canadian P/N 101953488) or equivalent to the threads of the exhaust manifold bolts.
  3. Install the exhaust manifold, NEW gasket and bolts.

    4. Tighten

    1. Tighten the exhaust manifold bolts a first pass to 15 N·m (11 lb ft). Tighten the exhaust manifold bolts beginning with the center two bolts. Alternate from side-to-side, and work toward the outside bolts.
    2. Tighten the exhaust manifold bolts a final pass to 25 N·m (18 lb ft). Tighten the exhaust manifold bolts beginning with the center two bolts. Alternate from side-to-side, and work toward the outside bolts.
  4. Install the spark plug wires. Refer to Spark Plug Wire Replacement .
  5. Using a flat punch, bend over the exposed edge of the exhaust manifold gasket at the rear of the left cylinder head.
  6. Raise the vehicle.

    7. Object Number: 664832 Size: SH
  7. Install the exhaust manifold pipe nuts.

    8. Tighten
    Tighten the nuts to 50 N·m (37 lb ft).

  8. Lower the vehicle.