C7.1 Marine Engine Caterpillar

Oil Pressure Is Low

Usage:

C7.1 JEZ

Use this procedure in order to troubleshoot low oil pressure. Also, use this procedure if one of the following event codes is active or logged.

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Table 1
J1939 Code and Description	Comments
100-1 Engine Oil Pressure : Low - most severe (3)	The engine is shut down. The code is logged.
100-17 Engine Oil Pressure : Low - least severe (1)	The code is logged.
100-18 Engine Oil Pressure : Low - moderate severity (2)	The code is logged.

If the engine shuts down due to a low oil pressure, power to the Electronic Control Module (ECM) must be cycled before restarting the engine.

Probable Causes

Codes
Oil level
Oil aeration
Oil viscosity
Oil filter
Oil pump
Sensors
Bypass valve
Oil cooler
Suction tube
Worn engine components

Recommended Actions

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Table 2
Troubleshooting Test Steps	Values	Results
1. Check for Codes A. Connect Caterpillar^® Electronic Technician (Cat ET) to the service tool connector. B. Look for active codes that are associated with the system for the event code.	Codes	Result: An associated code is active. Repair: Troubleshoot any associated codes before continuing with this test. Result: A code is active or logged. Proceed to Test Step 2.
2. Check the Engine Oil Level A. Refer to the Operation and Maintenance Manual, "Engine Oil Level - Check" for calibration of the dipstick gauge. The oil level can possibly be too far below the oil pump supply tube. The oil pump cannot supply enough lubrication to the engine components.	Oil Level	Result: The engine oil level is OK. Proceed to Test Step 3. Result: The engine oil level is low. Repair: Add engine oil in order to obtain the correct engine oil level. Refer to Operation and Maintenance Manual, "Engine Oil" for the recommendations of engine oil. Start the engine. Inspect the exterior of the engine for oil leaks. If the problem is not resolved, proceed to Test Step 3.
3. Check the Engine Oil for Aeration Note: Foamy oil on the dipstick is a good indication of aeration.	Aeration	Result: The oil is aerated. Proceed to Test Step 10. Result: The oil is not aerated. Proceed to Test Step 4.
4. Ensure that the Engine Oil Viscosity is Correct A. Obtain an S·O·S Oil Analysis to determine the characteristics of the oil.	Oil Viscosity	Result: The engine oil viscosity is correct. Proceed to Test Step 5. Result: The engine oil viscosity is not correct, or the oil is contaminated. Repair: Replace the engine oil. Refer to Operation and Maintenance Manual, "Engine Oil" for the recommendations of engine oil. Repair the cause of any engine oil contamination. If the problem is not resolved, proceed to Test Step 5.
5. Replace the Oil Filter	Filter	Result: Replace the engine oil filter. Repair: The oil filter was replaced. If the problem is not resolved, proceed to Test Step 6.
6. Check the Oil Pump Pressure A. Manually check the engine oil pressure. Refer to Testing and Adjusting, "Engine Oil Pressure - Test" for additional information.	Oil Pressure	Result: The oil pressure meets specifications. Proceed to Test Step 7. Result: The oil pressure does not meet specifications. Repair: Repair or replace the oil pump. If the problem is not resolved, proceed to Test Step 7.
7. Check the Engine Oil Pressure Sensor A. Remove the oil pressure sensor. B. Install a pipe "T" in the pressure sensor port. C. Install a manual gauge on one side of the pipe "T". Install the oil pressure sensor on the other side of the pipe "T". D. Start the engine and compare the two readings. The pressure reading must be within ±13.8 kPa (±2 psi).	Sensor	Result The pressure is within ±13.8 kPa (±2 psi). Proceed to Test Step 8. Result The pressure is not within ±13.8 kPa (±2 psi). Repair: Replace the sensor. If the problem is not resolved, proceed to Test Step 8.
8. Check the Oil Cooler for a Restriction A. Check the inlet side of the oil cooler for debris or blockage.	Restriction	Result: There was not debris or restrictions in the oil cooler. Proceed to Test Step 9. Result: There was debris or restrictions in the oil cooler. Repair: Clean or replace the oil cooler. If the problem is not resolved, proceed to Test Step 9.
9. Check the Suction Tube A. Remove the oil pan. B. Inspect the suction tube. Check the joints of the tube for cracks or for a damaged O-ring seal at the connection to the pump. C. Inspect the inlet screen of the suction tube for a restriction. This restriction will cause cavitation and a loss of engine oil pressure.	Suction Tube	Result: The suction tube and seal are OK. Proceed to Test Step 10. Result: The suction tube and seal are not OK. Repair: Clear the obstruction. Repair or replace damaged suction tube components. If the problem is not resolved, proceed to Test Step 10.
10. Check for Worn Engine Components A. Check for excessive clearance for the following: - Oil pump gears - Camshaft bearings - Crankshaft bearings - Rocker arm to rocker arm shaft	Damaged or Worn Engine Components	Result: Excessive clearance was identified for an engine component. Repair: Replace the worn engine components. 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).