479676 Volvo.Penta Fuel pipe

Probable Causes
Maintenance intervals and/or incorrect oil
Oil contamination
Oil pressure
Leaks
Fuel filtersRecommended Actions
Table 1
Troubleshooting Test Steps Values Results
1. Check for Incorrect Maintenance Intervals and/or Incorrect Oil
Maintenance Intervals
Result: The engine oil was changed at the interval that is recommended by the engines Operation and Maintenance Manual and S O S oil analysis.
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.
Repair: Use at least the minimum grade of Cat® oil.
Change the engine oil at the interval that is recommended. Repair or replace damaged components.
If the problem is not resolved, proceed to Test Step 2.
2. Check for Contaminated Engine Oil
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 for the following:
- Weak or broken spring
- Operating correctly
Note: If the oil filter bypass valve is open, the oil will not be filtered. Refer to the Disassembly and Assembly manual for additional information. Refer to the Cat guidelines for Reusability and Salvage/Repair manual for additional information.
Contamination
Result: The oil is not contaminated.
Proceed to Test Step 3.
Result: The oil is contaminated.
Repair: Perform the following procedure:
1. Determine the reason for any contamination of the engine oil. Repair or replace damaged engine components.
2. Drain the crankcase and refill the crankcase with clean engine oil.
3. Install new engine oil filters. Refer to the engines Operation and Maintenance Manual for additional information.
If the problem is not resolved, proceed to Test Step 3.
3. Check for Low Oil Pressure
Note: High engine oil level can be an indication of contamination with fuel or coolant. Engine oil that is contaminated with another liquid will cause low engine oil pressure.
A. 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.
Restriction
Result: The suction tube is OK.
Proceed to Test Step 4.
Result: The suction tube is NOT OK.
Repair: Clear the obstruction. Repair or replace suction tube.
If the problem is not resolved, proceed to Test Step 4.
4. Check the Inlet Air System for Leaks
Note: A leak in the air intake system may allow unfiltered air into the engine.
A. Inspect the following air system components:
- Gaskets
- Connections
Note: Streaks which may indicate a leakage of unfiltered air.
Air Leaks
Result: The inlet air system is OK.
Proceed to Test Step 5.
Result: The inlet air system is NOT OK.
Repair: Repair or replace damaged inlet air system components.
If the problem is not resolved, proceed to Test Step 5.
5. Inspect the Fuel Filters for Contamination
A. Remove the fuel filters. Inspect the fuel filters for contamination.
B. Obtain a fuel analysis.
Note: Contaminants in the fuel such as hydrogen sulfide and sulfur can lead to the formation of acids in the crankcase.
Fuel Filters
Result: The fuel filters are contaminated.
Repair: Determine the cause of any contamination.
Replace fuel filters. Refer to the Operation and Maintenance Manual for additional information.
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).