Cleaning and Inspection Procedure - Required

Cylinder Head

1. Courtesy of GENERAL MOTORS COMPANY

   Remove any old sealant or gasket material.

2. Clean all cylinder head surfaces with non-corrosive cleaning solvent.
WARNING:

Refer to Safety Glasses Warning .

3. Blow out all the oil galleries using compressed air.
4. Remove any carbon deposits from the combustion chamber (2).
5. Inspect the cylinder head sealing surface for flatness using a straightedge (1). If the cylinder head sealing surface is uneven, replace the cylinder head. Do NOT machine the cylinder head.
6. Inspect all the threaded holes for damage. Threads may be reconditioned with thread inserts.
7. Inspect the cylinder head camshaft bearing surfaces for the following conditions:
   1. Excessive scoring or pitting.
   2. Discoloration from overheating.
   3. Deformation from excessive wear.
8. If any of the above conditions exist on the camshaft bearing surfaces, replace the cylinder head.

9. Courtesy of GENERAL MOTORS COMPANY

   Inspect the cylinder head (1) for the following:

   1. Cracks, damage, or pitting in the combustion chambers.
   2. Debris in the oil galleries, continue to clean the galleries until all debris is removed.
   3. Coolant leaks or damage to the deck face sealing surface, if coolant leaks are present, measure the surface warpage as described under cylinder head measurement deck flatness inspection.
   4. Damage to any gasket surfaces.
   5. Burnt or eroded areas in the combustion chamber.
   6. Cracks in the exhaust ports (3) and combustion chambers.
   7. External cracks in the water passages.
   8. Restrictions in the intake or exhaust ports (3).
   9. Restrictions in the cooling system passages.
   10. Rusted, damaged or leaking core plugs.
10. Inspect the exterior of the camshaft housing ladder frame (2) for the following conditions:
    1. Damage to the camshaft housing ladder frame (4) bolt holes.
    2. Damage to the injector bore holes.
    3. Damage to the oil passages.
11. Inspect the interior of the camshaft housing ladder frame (2) for the following conditions:
    1. Inspect the camshaft housing ladder frame (2), casting imperfections, cracks or damage.
    2. Inspect the camshaft housing ladder frame (2) seal locations (1) for cracks or damage.
12. If the cylinder head (1) or ladder frame (2) is cracked or damaged, they must be replaced. No welding or patching of the is allowed.

Valves

1. Courtesy of GENERAL MOTORS COMPANY

   Clean the valves of carbon and oil. Carbon can be removed with a wire brush.

2. Inspect the valves for the following conditions:
   1. Inspect the valve faces for burning and cracking (1). If pieces are broken, replace the valve and inspect the corresponding piston and cylinder head area for damage.
   2. Inspect the valve for straightness and distortion (2). A distorted valve must be replaced.
   3. Inspect the valve stem for wear (3).
   4. Inspect the valve key grooves for chipping (4) and valve stem tip (5). Replace the valve if chipped or worn.

3. Courtesy of GENERAL MOTORS COMPANY

   Using a slide gauge (1), measure the valve length. Engine Mechanical Specifications

4. Courtesy of GENERAL MOTORS COMPANY

   Using a micrometer gauge (2), measure the valve stem diameter. Engine Mechanical Specifications