BEARING (.020 UNDERSIZE) 4S8883 - Caterpillar

Probable Causes
Oil level
Oil leaks
Internal engine wear
Incorrect oil viscosity
Turbocharger sealsRecommended 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 the Crankcase for Excessive Oil
A. Check the engine oil level. Too much oil in the engine crankcase can cause the engine to consume oil.
B. Ensure that the level indicator is calibrated correctly for the installation.
Oil Level
Result: The oil level is correct and the level indicator is correctly calibrated.
Proceed to Test Step 2.
Result: The oil level is high or the level indicator is incorrectly calibrated.
Repair: Remove excessive engine oil from the crankcase.
2. Check for External Engine Oil Leaks
A. Check for oil leaking on the outside of the engine.
Oil Leaks
Result: There are oil leaks on the outside of the engine.
Repair: Find the source of the oil leaks and perform the necessary repairs.
Verify that the repair eliminated the problem.
Result: There are no oil leaks on the outside of the engine.
Proceed to Test Step 3.
3. Inspect the Engine for Oil Leaks in the Combustion Area of the Cylinder
A. Check for oil leaks in the combustion area of the cylinders. Inspect the following components for wear:
- Damaged piston
- Worn piston ring
- Worn cylinder liners
- Worn valve guides
- Damaged cylinder head
B. Check for excessive engine blowby. Excessive engine blowby is an indicator of excessive engine wear or damaged internal engine components. Excessive blowby will cause unnecessary oil consumption.
Internal Engine Wear
Result: There are oil leaks in the combustion area of the cylinder.
Repair: Perform the necessary repairs. Replace parts, if necessary.
Verify that the repair eliminated the problem.
Result: There are no oil leaks in the combustion area of the cylinder.
Proceed to Test Step 4.
4. Ensure that the Correct Oil Viscosity is Being Used
A. Excessive consumption of engine oil can result if engine oil with the wrong viscosity is used. Engine oil with a thin viscosity can be caused by fuel leakage into the crankcase or by increased engine temperature.
Oil Viscosity
Result: The engine oil viscosity is correct.
Proceed to Test Step 5.
Result: The engine oil viscosity is not correct.
Repair: Replace the engine oil.
Verify that the repair eliminated the problem.
5. Inspect the Turbocharger
A. Check the turbocharger seals for leakage. Visually inspect the turbine and compressor wheels for oil.
Turbocharger Seals
Result: The turbocharger seals are leaking.
Repair: Perform the necessary repairs. Replace parts, if necessary.
Verify that the repair eliminated the problem.
If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).