Cylinder Head Cleaning and Inspection L98, LS2

Tools Required

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





Important: 

•	When cleaning a cylinder head in a thermal type oven, do not exceed 204°C (400°F).

•	Be careful not to scuff the chamber.

1. Clean the following components:

•	Use a commercially available rotary wire brush in order to remove the carbon from the combustion chambers.

•	Gasket surfaces

•	Refer to Replacing Engine Gaskets.

•	Valve stems and heads on a buffing wheel.

•	Bolt hole threads.

•	Remove all dirt, debris, or threadlocking material from the bolt holes.

2. Inspect the cylinder head for the following conditions:

2.1.	Cracks in the exhaust ports and combustion chambers.

2.2.	External cracks in the water chambers.

2.3.	Gasket surfaces for above acceptable scratches or gouging.

Refer to Replacing Engine Gaskets.

2.4.	Bolt hole threads for debris or damaged threads

Refer to Thread Repair and Thread Repair Specifications.




3. Check the cylinder head deck and the inlet and exhaust manifold mating surfaces for distortion. Use a set of feeler gauges (1) and a straight edge (2). Check along the length (A), laterally (B) and diagonally (C).
4. Check the flatness of the cylinder block and cylinder head deck surfaces. If the measurement is not within specification, the cylinder block must be replaced. machining is not recommended. Refer to Engine Mechanical Specifications.



5. Measure the overall height of the cylinder head (A) and ensure it is within the specified limit. Refer to Engine Mechanical Specifications.

Cylinder Head Cleaning and Inspection LS3

Tools Required

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





Important: 

•	When cleaning a cylinder head in a thermal type oven, do not exceed 204°C (400°F).

•	Be careful not to scuff the chamber.

1. Clean the following components:

•	Use the J 8089 in order to remove the carbon from the combustion chambers.

•	Gasket surfaces

•	Refer to Replacing Engine Gaskets.

•	Valve stems and heads on a buffing wheel

•	Bolt hole threads

•	Remove all dirt, debris, or threadlocking material from the bolt holes.

2. Inspect the cylinder head for the following conditions:

2.1.	Cracks in the exhaust ports and combustion chambers

2.2.	External cracks in the water chambers

2.3.	Gasket surfaces for excessive scratches or gouging

Refer to Replacing Engine Gaskets.

2.4.	Bolt hole threads for debris or damaged threads

Refer to Thread Repair or Thread Repair Specifications.




3. Inspect the cylinder head for warpage. Refer to Engine Mechanical Specifications.



4. Use the J 9666 in order to measure the valve spring tension. Refer to Engine Mechanical Specifications.



5. Inspect for a leaking plug. Second design applications use a rivet-type plug at the top rear coolant passage of each cylinder head. If service of a leaking plug is required, it is necessary to remove the cylinder head from the engine to properly remove the plug. Refer to Cylinder Head Disassemble