GM Service Manual Online
For 1990-2009 cars only

Exhaust Manifold Replacement 4.2L

Removal Procedure

  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle.

  2. Object Number: 750208  Size: SH
  3. Loosen and remove the exhaust pipe bolts from the exhaust manifold.
  4. Lower the vehicle.
  5. Remove the manifold heat shield. Refer to Exhaust Manifold Heat Shield Replacement.

  6. Object Number: 637625  Size: SH
  7. Loosen and remove the exhaust manifold bolts.
  8. Remove the exhaust manifold.
  9. Remove the exhaust manifold gasket.

Installation Procedure


    Object Number: 637622  Size: SH
  1. Install a new exhaust manifold gasket.

  2. Object Number: 715596  Size: SH
  3. Install the exhaust manifold.
  4. Caution: Refer to Fastener Caution in the Preface section.

  5. With threadlock GM P/N 12345493 (Canadian P/N 10953488) on the manifold bolts, install the bolts onto the manifold.
  6. 3.1. Tighten the exhaust manifold bolts first pass in sequence to 20 N·m (15 lb ft).
    3.2. Tighten the exhaust manifold bolts second pass in sequence to 20 N·m (15 lb ft).
    3.3. Tighten the exhaust manifold bolts final pass in sequence to 20 N·m (15 lb ft).

    Object Number: 637627  Size: SH
  7. Install the exhaust manifold heat shield studs, if required and tighten to 10 N·m (89 lb in).
  8. Install the manifold heat shield. Refer to Exhaust Manifold Heat Shield Replacement.
  9. Raise the vehicle.

  10. Object Number: 758044  Size: SH
  11. Install the exhaust pipe to the manifold with seal and secure the pipe with the nuts. Tighten the exhaust pipe nuts to 50 N·m (37 lb ft).
  12. Lower the vehicle.