SWITCH AS-ROCKER 2577285 - Caterpillar

Probable Causes
Engine accessories
Valve train components
Connecting rod bearings
Crankshaft bearingsRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Table 1
Troubleshooting Test Steps Values Results
1. Engine Accessories
A. Check for damaged engine accessories. Isolate the source of the noise. Remove the suspect engine accessories. Inspect the suspect engine accessories.
Engine accessories
Result An engine accessory is the source of the noise.
Repair the engine accessory and/or replace the engine accessory, if necessary.
Result An engine accessory is not the source of the noise.
Proceed to Test Step 2.
2. 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:
- Camshaft
- Valve rotocoil
- Valve springs
- Camshaft followers
- Rocker shaft
- Bridges
- Pushrods
- Injectors
Refer to the Disassembly and Assembly for additional information.
C. Check for valves that do not move freely. Remove the cylinder head and inspect the valves.
Refer to the Disassembly and Assembly for additional information.
Valve train
Result: The valve train components are not damaged.
Proceed to Test Step 8.
Result: The valve train components are damaged.
Make the necessary repairs. Verify that the repair eliminated the problem.
3. Connecting Rod Bearings
A. Inspect the connecting rod bearings and the crankshaft pins for scoring. Check the piston pin for excessive wear.
Rod bearings
Result: The connecting rod bearings are not damaged.
Proceed to Test Step 4.
Result: The connecting rod bearings are damaged.
Make the necessary repairs. Verify that the repair eliminated the problem.
4. Crankshaft
A. Inspect the crankshaft and the related components. Look for worn thrust plates and wear on the crankshaft.
B. Inspect the connecting rod bearings and the bearing surfaces on the crankshaft. Make sure that the bearings are in the correct position.
C. Check the counterweight bolts.
Crankshaft
Result: The crankshaft or the related components are damaged or worn.
Repair or replace any damaged parts. Verify that the repair eliminated the problem.