PISTON 4B9000 - Caterpillar

Probable Causes
Active codes and logged codes
Electrical connections
Fuel injection
Fuel quality
Proper lubrication
Isolate the source of the noise.
Valve train components
Gear train and lower end components
CrankshaftRecommended Actions
Table 1
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Establish communication between Cat® Electronic Technician (ET) and the Electronic Control Module (ECM). Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Download the "Warranty Report" from the ECM before performing any troubleshooting or clearing codes.
Codes
Result: There are no active codes.
Proceed to Test Step 2.
Result: There are active codes.
Repair: Troubleshoot any active codes before continuing with this procedure.
2. Check the Electrical Connections
A. Check for the correct installation of the ECM J1/P1 and the J2/P2 connectors. Check for correct installation of the fuel injector connectors.
Connectors
Result: There are no suspect connectors.
Proceed to Test Step 3.
Result: There are suspect connectors.
Repair: Repair connectors that are suspect or replace connectors that are suspect.
Perform the "Wiggle Test" on Cat ET.
3. Fuel Injection
C13, C15, and C18 Applications
A. Perform the "Injector Solenoid Test" on Cat ET in order to determine if all of the injector solenoids are being energized by the ECM.
B. Access the "Cylinder Cutout Test" in the "Diagnostic Tests" under the "Diagnostics" menu.
C. Perform the "Automatic Cylinder Cutout Test" on Cat ET.
C9.3 Applications
A. Perform the "Fuel System Verification Test" in the "Diagnostic Tests" under the "Diagnostics" menu.
Injector Solenoid Test or Fuel System Verification Test
Result: The test was successful.
Proceed to Test Step 4.
Result: The test was not successful.
Repair: Diagnose the problem and then repair the problem.
Reset all active codes and clear all logged codes.
Verify that the repair eliminated the problem.
4. Fuel Quality
A. Refer to Operation and Maintenance Manual for information on the proper characteristics of the fuel for the engine. If necessary, obtain a fuel analysis in order to confirm that the correct fuel is being used for the engine. Refer to Systems Operation/Testing and Adjusting, "Fuel System Quality Test" for the proper procedure.
Fuel
Result: The fuel quality is OK.
Proceed to Test Step 5.
Result: The fuel quality is not OK.
Repair: Replace the fuel. Verify that the repair eliminated the problem.
5. Proper Lubrication
A. Check for proper lubrication of the valve components. Check for sufficient lubrication between the injector tappets and the rocker arms.
B. Check for blocked oil passages. Oil passages must be clean. Clean any oil passages that are questionable. Refer to the Disassembly and Assembly for additional information.
C. Inspect the engine oil filters for ferrous material.
D. Obtain an S-O-S oil analysis. The analysis will contribute to a better understanding of oil contamination and the origin of the contamination.
Lubrication
Result: The oil passages are not blocked and the engine has proper lubrication.
Proceed to Test Step 6.
Result: The oil passages are blocked or the engine does not have proper lubrication.
Repair: Make the necessary repairs, Verify that the repair eliminated the problem.
6. Isolate the Source of the Noise
A. If the source of the noise is the engine accessory, remove the suspect engine accessory. Inspect the suspect engine accessory.
Engine Accessory
Result An