GM Service Manual Online
For 1990-2009 cars only

    Object Number: 521830  Size: SH

    Caution: Wear safety glasses in order to avoid eye damage.

  1. Clean the exhaust manifolds in cleaning solvent.
  2. Dry the components with compressed air.
  3. Inspect the exhaust manifolds for the following:
  4. • Damage to the gasket sealing surfaces (1)
    • Damage to the exhaust gas recirulation (EGR) pipe fitting (2) (left manifold)
    • Damage to the take down bolt hole threads (3)
    • Broken or damaged exhaust manifold heat shields (4) (if applicable)
    • Restrictions within exhaust passages
    • Damaged or cracked exhaust manifold

    Object Number: 66607  Size: SH
  5. Measure the alignment or surface flatness of the exhaust manifold flanges, using a straight edge and a feeler gauge. Refer to Engine Mechanical Specifications.
  6. If the surface flatness is not within specifications, the exhaust manifold is warped and must be replaced.


    Object Number: 521830  Size: SH

    Caution: Wear safety glasses in order to avoid eye damage.

  1. Clean the exhaust manifolds in cleaning solvent.
  2. Dry the components with compressed air.
  3. Inspect the exhaust manifolds for the following:
  4. • Damage to the gasket sealing surfaces (1)
    • Damage to the exhaust gas recirculation (EGR) pipe fitting (2) (left manifold)
    • Damage to the take down bolt hole threads (3)
    • Broken or damaged exhaust manifold heat shields (4), if applicable
    • Restrictions within exhaust passages
    • Damaged or cracked exhaust manifold

    Object Number: 66607  Size: SH
  5. Measure the alignment or surface flatness of the exhaust manifold flanges, using a straight edge and a feeler gauge. Refer to Engine Mechanical Specifications .
  6. If the surface flatness is not within specifications, the exhaust manifold is warped and must be replaced.