Cylinder Head Cleaning and Inspection

Cylinder Head Cleaning and Inspection

Cleaning Procedure

1. Remove any old thread sealant, gasket material or sealant.

2. Clean all cylinder head surfaces with non-corrosive sealant.

Warning: Refer to Safety Glasses Warning Safety Glasses Warning.


3. Blow out all the oil galleries using compressed air.

4. Remove any carbon deposits from the combustion chamber.

Visual Inspection

1. Inspect the cylinder head camshaft bearing surfaces for the following conditions:

* Excessive scoring or pitting

* Discoloration from overheating

* Deformation from excessive wear

* If the camshaft bearing journals appear to be scored or damaged, you must replace the cylinder head. DO NOT machine the camshaft bearing journals.

2. If any of the above conditions exist on the camshaft bearing surfaces, replace the cylinder head.

3. Inspect the cylinder head for the following:

* Cracks, damage or pitting in the combustion chambers.

* Debris in the oil galleries - Continue to clean the galleries until all debris is removed.

* Coolant leaks or damage to the deck face sealing surface - If coolant leaks are present, measure the surface war page as described under cylinder head measurement - deck flatness inspection.

* Damage to any gasket surfaces.

* Burnt or eroded areas in the combustion chamber.

* Cracks in the exhaust ports and combustion chambers.

* External cracks in the water passages.

* Restrictions in the intake or exhaust passages.

* Restrictions in the cooling system passages.

* Rusted, damaged or leaking core plugs.

4. If the cylinder head is cracked or damaged, it must be replaced. No welding or patching of the cylinder head is allowed.

Valve Inspection And Measurement




1. 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). Distorted valve must be replaced.

3. Inspect the valve stem for wear (3).

4. Inspect the valve key grooves for chipping and wear (5). Replace the valve if chipped or worn.




3. Measure the valve length (2). Use a slide gauge (1). Refer to Engine Mechanical Specifications Service Limits & General Specifications to find the permitted values.




4. Measure the valve stem diameter. Use a micrometer gauge (2). Refer to Engine Mechanical Specifications Service Limits & General Specifications to find the permitted values. Note the measurement results.

Cylinder Head Measurement




1. Inspect the cylinder head sealing surface for flatness. Use a straightedge (1). Refer to Engine Mechanical Specifications Service Limits & General Specifications to find the permitted values. If the measurement does not show the permitted value, replace the cylinder head. Machining is NOT allowed.

2. Measure the valve guide inner diameter. Note the measurement results. Refer to Engine Mechanical Specifications Service Limits & General Specifications to find the permitted values.

3. Subtract the valve stem diameter from valve guide inner diameter to calculate the valve stem to guide clearance. Refer to Engine Mechanical Specifications Service Limits & General Specifications to find the permitted values.

4. Turn the cylinder head upside down.