HEAD 9T3964 - Caterpillar

Probable Causes
Lubrication is inadequate
Valve lash is out of adjustment
Valve train componentsRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in the order of the listed test steps.
Table 1
Troubleshooting Test Steps Values Results
1. Check for Adequate Lubrication
A. Check the lubrication in the valve compartment. Ensure that there is adequate engine oil flow in the valve compartment. The passages for the engine oil must be clean.
Lubrication
Result: The lubrication system is OK.
Proceed to the next step.
Result: The lubrication system is NOT OK.
Restore adequate oil flow.
If the problem is not resolved, proceed to the next step.
2. Check the Valve Lash
Lash
Result: The lash setting is OK.
Proceed to the next step.
Result: The lash setting is NOT OK.
Adjust the engine valve lash. Refer to the engine Systems Operation/Testing and Adjusting manual.
If the problem is not resolved, proceed to the next step.
3. Inspect the Valve Train Components
A. Inspect the following components of the valve train:
- Rocker arms
- Pushrods
- Valve lifters
- Camshaft
- Valve stems
- Rocker shafts
Check the components for the following conditions:
- Straightness
- Abnormal wear
- Excessive wear
- Cleanliness
Components Result: A component is NOT OK.
Replace parts, if necessary.
Adjust the engine valve lash. Refer to the engine Systems Operation/Testing and Adjusting manual.
Note: If the camshaft is replaced, then replacing the valve lifters is mandatory.