GM Service Manual Online
For 1990-2009 cars only

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


    Object Number: 1252185  Size: SH
  1. Make sure the gasket surfaces of the cylinder head and the engine block are free of nicks and heavy scratches.
  2. Inspect the cylinder head gasket and the mating surfaces for leaks, corrosion, and blow-by.
  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.
  5. Check the sealing surfaces for deformation and warpage. The cylinder head sealing surfaces must be flat within 0.025 mm (0.001 in) maximum.

  6. Object Number: 1252186  Size: SH
  7. Measure the height of the cylinder head from sealing surface to sealing surface. The cylinder head height should be 133.975-134.025 mm (5.274-5.276 in). If the cylinder head height is less than 133.9 mm (5.271 in), replace the cylinder.
  8. Inspect the threaded holes for damage.
  9. Inspect the valve seats for excessive wear and burned spots.