PISTON 6Y2428 - Caterpillar

Probable Causes
Diagnostic codes
Fuel quality
Valve train components
Injectors
PistonsRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Table 1
Troubleshooting Test Steps Values Results
1. Diagnostic Codes
A. Establish communication between the electronic service tool and the Electronic Control Module (ECM).
B. Check for active diagnostic codes.
Codes
Result: A diagnostic trouble code is active or logged.
Repair: Troubleshoot the active or logged codes. Refer to Troubleshooting, "Diagnostic Trouble Codes".
Result: A diagnostic trouble code is not active or logged.
Proceed to Test Step 2.
2. Fuel Quality
A. Check the fuel quality. Refer to Systems Operation, Testing, and Adjusting, "Fuel Quality - Test".
B. Refer to Operation and Maintenance Manual for information on the proper characteristics of the fuel for the engine.
Fuel
Result: The fuel quality is not OK.
Repair: Drain the fuel system and replace the fuel filters. Refer to the Operation and Maintenance Manual, "Fuel System Primary Filter (Water Separator) Element - Replace" and Operation and Maintenance Manual, "Fuel System Filter - Replace".
Fill the fuel system with fuel that meets the standard in the Operation and Maintenance Manual, "Fluid Recommendations".
Prime the fuel system. Refer to the Operation and Maintenance Manual, "Fuel System - Prime".
Verify that the procedure has eliminated the noise.
Result: The fuel quality is OK.
Proceed to Test Step 3.
3. Valve Train Components
A. Check the valve lash. Refer to Troubleshooting, "Valve Lash Is Excessive".
B. Check for damage to valve train components. Remove the valve cover from the suspect cylinders. Check the following items for damage:
Valve springs
Rocker shaft
Pushrods
Camshaft followers
Refer to the Disassembly and Assembly for additional information.
Valve train
Result: Valve train components are damaged.
Repair: Make the necessary repairs, Verify that the repair has eliminated the noise.
Result: The valve train components are not damaged.
Proceed to Test Step 4.
4. Electronic Unit Injectors
A. Use the electronic service tool to check for active diagnostic codes that relate to the electronic unit injectors. Troubleshoot any active diagnostic codes before continuing with this procedure.
Diagnostic codes
Result: There is an active diagnostic code for the injectors.
Repair: Troubleshoot any active injector diagnostic codes. Refer to Troubleshooting, "Diagnostic Trouble Codes".
Result: There are no active diagnostic codes for the injectors.
Proceed to Test Step 5.
5. Pistons
A. Inspect the pistons for damage and wear.
Pistons
Result: One or more pistons are worn or damaged.
Repair : Replace any worn or damaged parts.
Verify that the repair has eliminated the noise.
Result: All pistons are OK.
Contact the Dealer Solution Network (DSN).