3176C, 3406E and 3456 Industrial Engines Troubleshooting – Engine Has Early Wear

A. Use engine oil that is recommended and change the engine oil at the interval that is recommended by the engines Operation and Maintenance Manual.

Proceed to Test Step 2.

Result: The engine oil was not changed at the interval that is recommended by the engines Operation and Maintenance Manual.

Use at least the minimum grade of Cat oil.

Change the engine oil at the interval that is recommended. Repair or replace any damaged parts.

A. Obtain an S-O-S oil analysis. The analysis will contribute to a better understanding of oil contamination.

B. Check the oil filter bypass valve.

If the oil filter bypass valve is open, the oil will not be filtered. Check the oil filter bypass valve for a weak spring or for a broken spring. If the spring is broken, replace the spring. Verify that the oil bypass valve is operating correctly. Refer to the Disassembly and Assembly manual.

Refer to the Caterpillar guidelines for “Reusability and Salvage/Repair” for determining if the replacement of parts is necessary in order to perform a quality repair.

Determine the reason for any contamination of the engine oil and make the necessary repairs. Drain the crankcase and refill the crankcase with clean engine oil. Install new engine oil filters. Refer to the engines Operation and Maintenance Manual.

Result: The oil is not contaminated.

Proceed to Test Step 3.

A. Engine oil that is contaminated with another liquid can cause low engine oil pressure. High engine oil level can be an indication of contamination. Obtain an analysis of the engine oil.

B. The inlet screen of the suction tube for the engine oil pump can have a restriction. This restriction will cause cavitation and a loss of engine oil pressure. Check the inlet screen on the suction tube and remove any material that may be restricting engine oil flow.

When some components of the engine show wear in a short time, the cause can be a restriction in a passage for engine oil. An indicator for the engine oil pressure may indicate sufficient pressure, but a component is worn due to a lack of lubrication. In such a case, look at the passage for the engine oil supply to the component. Refer to Systems Operation/Testing and Adjusting, “Lubrication System” for additional information.

Clear the obstruction. Verify the repair.

Result: The inlet tube does not have a restriction.

Proceed to Test Step 4.

A. A leak in the air intake system may allow unfiltered air into the engine. Inspect the air intake system for streaks which may indicate a leakage of unfiltered air. Inspect all of the gaskets and the connections.

Proceed to Test Step 5.

Result: There are air leaks.

Repair any leaks.

A. Remove the fuel filters. Inspect the fuel filters for contamination. Contaminants in the fuel such as hydrogen sulfide and sulfur can lead to the formation of acids in the crankcase. Obtain a fuel analysis.

Determine the cause of any contamination and make the necessary repairs.

Install new fuel filters. Refer to the Operation and Maintenance Manual.