Possible Causes
• Lubrication
• Valve Train Components
Suggested Actions
Note: The steps are listed below in order of probability. Perform these steps in sequence.
Troubleshooting and Repair Test Steps
1. Lubrication
A. Remove the valve cover. Refer to Disassembly and Assembly, “Valve Cover – Removal and Installation” for correct procedures.
B. Turn the engine around to check the lubrication in the valve chamber. Ensure there is sufficient engine oil flow in the valve chamber. The engine oil passages must be clean.
Note: Do not run the engine while the valve cover is removed.
Result: Insufficient oil flow in the valve mechanism.
Repair: Ensure the engine oil passages are clean.
Result: Normal oil flow in the valve mechanism.
Proceed to Test Step 2. 2. Valve Train Components
A. Inspect the following valve train components for abnormalities or excessive wear, and check their straightness and cleanliness:
· Rocker arm
· Valve bridge
· Pushrod
· Hydraulic lifter
· Camshaft
· Valve stem
· Rocker arm shaft
Result: Valve train components are worn, bent, or unclean.
Repair: Repair or replace the components.
Refer to disassembly and assembly.
Note: If the camshaft is replaced,
a new valve lifter must also be installed.
Result: All valve train components are normal.
Please contact the Dealer Solutions Network (DSN).
