GEAR,HELICAL 9S6506 - Caterpillar

Probable Causes
Lubrication
Valve train components
Valve lashRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Table 1
Troubleshooting Test Steps Values Results
1. Lubrication
A. Remove the valve mechanism cover. Refer to Disassembly and Assembly, "Valve Mechanism Cover - Remove and Install" for the correct procedure.
B. Crank the engine and 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.
Note: Do not run the engine with the valve mechanism cover removed.
Lubrication
Result: The oil flow to the valve mechanism is insufficient.
Repair: Make sure that the passages for the engine oil are clear.
Result: The oil flow to the valve mechanism is OK.
Proceed to Test Step 2.
2. Valve Train Components
A. Inspect the following components of the valve train for abnormal or excessive wear, straightness, and cleanliness:
Rocker arms
Valve bridges
Pushrods
Valve lifters
Camshaft
Valve stems
Rocker shafts
Valve train components
Result: A valve train component is worn, bent, or not clean.
Repair: Repair or replace the component. Refer to Disassembly and Assembly.
Note: If the camshaft is replaced, new valve lifters must also be installed.
Result: All the valve train components are OK.
Proceed to Test Step 3.
3. Valve Lash
A. Check the valve lash of the engine.
Valve lash
Result: The valve lash is not within specification.
Repair: Adjust the valve lash of the engine. Refer to Systems Operation, Testing and Adjusting, "Engine Valve Lash - Inspect/Adjust" for the correct procedure.
Result: The valve lash is within specification.
Contact the Dealer Solutions Network (DSN).