C7.1 Engines and Generator Sets Caterpillar

Oil Pressure Is Low

Usage:

C7.1 770

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NOTICE

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.

Note: Severe slopes can cause low oil pressure. If the machine is operated on severe slopes, the oil level in the engine crankcase must be at the "FULL" mark on the dipstick. Refer to the Operation and Maintenance Manual for details.

The Electronic Control Module (ECM) monitors the engine oil pressure. The following events are associated with low engine oil pressure:

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Table 1
Diagnostic Codes for Low Engine Oil Pressure
J1939 Code	CDL Code	Code Description (code descriptions may vary)	Comments
100-17	E360 (1)	Engine Oil Pressure : Low - least severe (1)	The ECM has been powered for at least 2 seconds. The engine has been running for at least 10 seconds. There are no diagnostic trouble codes for the oil pressure sensor. There are no diagnostic trouble codes for the 5 VDC supply. Refer to Illustration 1 for the trip point for the oil pressure.
100-18	E360 (2)	Engine Oil Pressure : Low - moderate severity (2)	The ECM has been powered for at least 2 seconds. The engine has been running for at least 10 seconds. There are no diagnostic trouble codes for the oil pressure sensor. There are no diagnostic trouble codes for the 5 VDC supply. The engine will be derated. Refer to Illustration 2 for the trip point for the oil pressure.
100-1	E360 (3)	Engine Oil Pressure : Low - most severe (3)	The ECM has been powered for at least 2 seconds. The engine has been running for at least 10 seconds. There are no diagnostic trouble codes for the oil pressure sensor. There are no diagnostic trouble codes for the 5 VDC supply. The engine will be derated. Refer to Illustration 3 for the trip point for the oil pressure.

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Illustration 1	g02856758
Diagnostic code 100-17 Engine Oil Pressure versus Engine Speed

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Illustration 2	g02856759
Diagnostic code 100-18 Engine Oil Pressure versus Engine Speed

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Illustration 3	g02856760
Diagnostic code 100-1 Engine Oil Pressure versus Engine Speed

Probable Causes

Engine oil level
Oil specification
Aerated oil
Engine oil pressure
Engine oil filter
Engine oil cooler
Fuel in the engine oil
Piston cooling jets
Engine oil suction tube
Engine oil pump pressure relief valve
Engine oil pump
Bearing clearance

Recommended Actions

Note: The procedures have been listed in order of probability. Complete the procedures in order.

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Table 2
Troubleshooting Test Steps	Values	Results
1. 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 2.
2. 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 3.
3. Aerated Oil A. Sample 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 9. Result: The oil is not aerated. Proceed to Test Step 4.
4. Engine Oil Pressure A. Check the actual engine oil pressure with a calibrated test gauge. Compare the oil pressure reading from the electronic service tool to the pressure on the test gauge.	Oil pressure	Result: The oil pressure reading from the electronic service tool and the pressure on the test gauge are different. Repair: Install a new oil pressure transmitter. Refer to Disassembly and Assembly, "Engine Oil Pressure Sensor - Remove and Install". Result: The oil pressure reading from the electronic service tool and the pressure on the test gauge are similar. Proceed to Test Step 5.
5. 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: Investigate the cause of the filter blockage. 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 6.
6. 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 7.
7. 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 8.
8. 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. Repair: 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 9.
9. 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. Attempt to identify the source of the debris. 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 10.
10. Engine Oil Pump Pressure Relief Valve A. Inspect the components of the pressure relief valve for excessive wear or damage.	Oil pump PRV	Result: A component in the pressure relief valve is not within specification. Repair: Repair or replace the pressure relief valve, as necessary. Refer to Disassembly and Assembly, "Engine Oil Relief Valve - Remove and Install". Result: The pressure relief valve 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. Contact the Dealer Solutions Network (DSN).