GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 HUMMER 🢒 2007 🢒 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.
  8. Clean and inspect the exhaust manifold, if the manifold is not being replaced. Refer to Exhaust Manifold Cleaning and Inspection .

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.
  9. Install the ignition coils. Refer to Ignition Coil Replacement .