Cylinder Head Disassemble L98, LS2

1. Remove the spark plugs from the cylinder heads. Refer to Spark Plug Replacement.




Important: 

•	With the components at room temperature.

•	Mark, organize, or sort the cylinder head components for assembly. Return the components to their original location during assembly.

2. Use a commercially available valve spring compressor in order to compress the valve spring.



3. Remove the valve stem keys (2).
4. Release the spring compressor and remove from the cylinder head (1).
5. Remove the valve spring cap (3).
6. Remove the valve spring (4).
7. Remove the valve (7).
8. Remove the valve stem oil seal (5). Refer to Separating Parts.
9. Repeat steps 2-8 for each valve as required.

Important: DO NOT remove the coolant core plugs (6) unless servicing is required. These will be damaged on removal and must be replaced.

10. Remove the cylinder head core hole plugs (6), as required.




Notice: Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.

11. Remove the ECT sensor (1) from the cylinder head.



12. Remove the coolant plug (2) from the right cylinder head (1).



13. Check all valve springs for distortion. There should be no more than 1.6 mm variance (1) of the spring end while the spring is being rotated on a flat surface.

Replace springs that exceed this specification.




14. Use a commercially available valve spring tester and measure each valve spring for free height and tension. Refer to Engine Mechanical Specifications.

Cylinder Head Disassemble LS3

Tools Required

J 8062 Valve Spring Compressor - Head Off

Important: 

•	With the components at room temperature, remove the spark plugs from the cylinder head.

•	Mark, organize, or sort the cylinder head components for assembly. Return the components to their original location during assembly.

1. Remove the spark plugs from the cylinder heads.
2. Use the J 8062 in order to compress the valve spring.



3. Remove the valve stem keys (225).
4. Remove the valve spring cap (224).
5. Remove the valve spring (223).
6. Remove the valves (228).
7. Remove the valve stem oil seal (222). Refer to Separating Parts.



8. Remove the cylinder head core hole plugs (216), as required.



9. Remove the coolant temperature sensor (725) from the left cylinder head.



10. Remove the cylinder head plug (229) from the right cylinder head.



11. 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.



12. Using a 6.43 mm (0.25 in) or smaller punch, remove the plug assembly from the cylinder head.



13. If plug removal is required, install a first design coolant air bleed cover and bolt to complete the repair.