471707 Volvo.Penta Reduction valve

Do not operate the engine with low oil pressure. Engine damage will result. If measured oil pressure is low, discontinue engine operation until the fault is corrected.
The Electronic Control Module (ECM) monitors the engine oil pressure.Probable Causes
Visible Leaks
Engine oil level
Oil specification
Engine oil filter
Engine oil pressure switch
Engine oil relief valve
Engine oil cooler
Fuel in the engine oil
Piston cooling jets
Engine oil suction tube
Engine oil pump
Bearing clearanceRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Table 2
Troubleshooting Test Steps Values Results
1. Visible Leaks
A. Thoroughly inspect the engine for oil leaks.
Visible leaks
Result: There are visible oil leaks.
Repair: Repair any leaks.
Result: There are no visible oil leaks
Proceed to Test Step 2.
2. Engine Oil Level
A. Check the engine oil level.
Oil level
Result: The engine oil level is low.
Repair: Fill the oil system to the full mark on the dipstick.
Result: The engine oil level is OK.
Proceed to Test Step 3.
3. Oil Specification
A. Check that engine oil of the correct specification is being used. Refer to the Operation and Maintenance Manual, "Refill Capacities and Recommendations".
Oil specification
Result: An incorrect specification of engine oil is being used.
Repair: Drain the oil system and refill the oil system with engine oil of the correct specification. Refer to Operation and Maintenance Manual, "Engine Oil and Filter - Change".
Result: The engine contains oil of the correct specification.
Proceed to Test Step 4.
4. Engine Oil Filter
A. Remove the engine oil filter. Refer to the Operation and Maintenance Manual, "Engine Oil and Filter - Change".
B. Inspect the engine oil filter for evidence of blockage.
Oil filter
Result: The oil filter is blocked.
Repair: Install a new oil filter. Refer to the Operation and Maintenance Manual, "Engine Oil and Filter - Change" for further information.
Result: The oil filter is OK.
Repair: Install a new oil filter. Refer to the Operation and Maintenance Manual, "Engine Oil and Filter - Change" for further information.
Proceed to Test Step 5.
5. Engine Oil Pressure Switch
A. Ensure that the engine oil pressure switch is operating correctly. Refer to Troubleshooting, "Switch Circuits - Test (Engine Oil Pressure Switch)".
Engine Oil Pressure Switch
Result: There is a fault with the oil pressure switch circuit.
Repair: Make any necessary repairs. Refer to Troubleshooting, "Switch Circuits - Test (Engine Oil Pressure Switch)".
Result: The oil pressure switch circuit is OK.
Proceed to Test Step 6.
6. Engine Oil Relief Valve
A. Inspect the engine oil relief valve for damage.
Damage
Result: The engine oil relief valve is damaged.
Repair: Replace the oil relief valve. Refer to Disassembly and Assembly, "Engine Oil Relief Valve - Remove and Install".
Result: The engine oil relief valve is OK.
Proceed to Test Step 7.
7. Engine Oil Cooler
A. Check the oil cooler for signs of damage or restrictions.
Oil cooler
Result: The oil cooler has signs of damage or restriction.
Repair: Install a new oil cooler. Refer to Disassembly and Assembly, "Engine Oil Cooler - Remove" and Disassembly and Assembly, "Engine Oil Cooler - Install".
Result: The oil cooler is OK.
Proceed to Test Step 8.
8. Fuel in the Engine Oil
A. Check fuel contamination of the engine oil. Refer to Troubleshooting, "Oil Contains Fuel".
Oil contamination
Result: The oil contains fuel.
Repair: Refer to Troubleshooting, "Oil Contains Fuel".
Result: The oil is not contaminated.
Proceed to Test Step 9.
9. Piston Cooling Jets
A. Inspect the piston cooling jets for cracks, damage, or missing jets.
Piston cooling jets
Result: A piston cooling jet is cracked, damaged, or missing.
Result: Install a new piston cooling jet. Refer to Disassembly and Assembly, "Piston Cooling Jets - Remove and Install".
Result: The piston cooling jets are OK.
Proceed to Test Step 10.
10. Engine Oil Suction Tube
A. Check the inlet screen on the oil suction tube and remove any material that may be restricting oil flow.
B. Check the joints of the oil suction tube for cracks or a damaged joint.
Note: Cracks or damage may allow air leakage into the supply to the oil pump.
Oil suction tube
Result: The inlet screen on the oil suction tube is blocked with debris.
Repair: Remove the debris from the inlet screen.
Result: The oil suction tube is cracked.
Repair: Install a new oil suction tube.
Result: The oil suction tube is OK.
Proceed to Test Step 11.
11. Engine Oil Pump
A. Inspect the components of the engine oil pump for excessive wear.
Oil pump
Result: A component in the oil pump is not within specification.
Repair: Repair the oil pump or replace the oil pump, if necessary. Refer to Disassembly and Assembly, "Engine Oil Pump - Remove" and Disassembly and Assembly, "Engine Oil Pump - Install".
Result: The oil pump is OK.
Proceed to Test Step 12.
12. Bearing Clearance
A. Inspect the engine components for excessive bearing clearance or damaged bearings. Inspect the following components for excessive bearing clearance:
Crankshaft main bearings
Connecting rod bearings
Camshaft front bearing
Idler gear bearing
Bearing clearance
Result: An engine bearing is not within specification.
Repair: Install a new bearing. Refer to Disassembly and Assembly.
Result: All engine bearings are within specification.
Repair: If the fault is still present there may be an open circuit condition in the oil pressure switch circuit. Refer to Troubleshooting, "Switch Circuits - Test (Engine Oil Pressure Switch)".