GM Service Manual Online
For 1990-2009 cars only

Cleaning Procedure

    Caution: Refer to Safety Glasses Caution in the Preface section.


    Object Number: 1240636  Size: SH
  1. Clean the cylinder head.
  2. Clean the valve guides.
  3. Clean all of the threaded holes.
  4. Clean the valves of carbon, oil, and varnish.

Inspection Procedure


    Object Number: 1224672  Size: SH
  1. Clean the sealing surfaces.
  2. Inspect the cylinder head gasket and the mating surfaces for leaks, corrosion, and blowby.
  3. Inspect the cylinder head for cracks.
  4. Inspect the length and the width of the cylinder head using a feeler gage and a straight edge (1).
  5. Inspect the sealing surfaces for damage and warping. The cylinder head sealing surfaces must be flat within 0.05 mm (0.0020 in) maximum.

  6. Object Number: 1240624  Size: SH
  7. Inspect all threaded holes for damage.
  8. Inspect the valve seats for excessive wear and burned spots.