GM Service Manual Online
For 1990-2009 cars only

    Object Number: 234438  Size: SH
  1. Inspect the intake manifold for damage.
  2. Inspect the intake manifold for cracks near the mounting holes (1-4).
  3. Inspect the crankcase ventilation passages for any blockage and clean as necessary.

  4. Object Number: 235498  Size: SH
  5. Clean the intake manifold mating surfaces.
  6. Use a straight edge and a feeler gage and measure the intake manifold mounting surface for warpage.
  7. Intake Manifold Maximum Warpage
    0.10 mm (0.0039 in)

  8. If the warpage is greater than the maximum, replace the intake manifold.