GM Service Manual Online
For 1990-2009 cars only

Cleaning Procedure

  1. Clean the exhaust manifold in solvent.
  2. Caution: Wear safety glasses in order to avoid eye damage.

  3. Dry the exhaust manifold with compressed air.

Inspection Procedure


    Object Number: 576683  Size: SH
  1. Inspect the exhaust manifold for the following:
  2. • Damage to the pipe flare (1)
    • Damage to the pipe flange (2)
    • Damage or excessive corrosion to the exhaust manifold exterior (3)
    • Damage to the converter pipe studs (4)
    • Damage to the converter pipe gasket sealing surfaces (5)

    Object Number: 576687  Size: SH
  3. Inspect the exhaust manifold for the following:
  4. • Damage to the oxygen sensor threaded hole (1)
    • Damage to the EGR pipe fitting (2)
    • Damage to the exhaust manifold mounting holes (3)
    • Damage to the gasket sealing surfaces (4)
    • Damage or restrictions within the exhaust passages (5)
    • Damage or broken welds
  5. Repair or replace the exhaust manifold and/or components as necessary.

  6. Object Number: 576690  Size: SH
  7. Measure the alignment or surface flatness of the exhaust manifold flanges, using a straight edge and a feeler gauge. Exhaust manifold surface flatness must not exceed 0.254 mm (0.010 in).
  8. If the surface flatness is not within specifications, the exhaust manifold is warped and must be replaced.