ENGINE AR-PRIMARY 3920442 - Caterpillar

Probable Causes
Engine oil cooler
Cylinder head gasket
Cylinder head
Cylinder blockRecommended Actions
Complete the procedure in the order in which the steps are listed.
Table 1
Troubleshooting Test Steps Values Results
1. Engine Oil Cooler
A. Drain the coolant from the cooling system. Drain the lubricating oil from the engine oil cooler. Refer to the Operation and Maintenance Manual for more information.
B. Check for leaks in the engine oil cooler. Refer to Systems Operation, Testing, and Adjusting, "Cooling System" for the correct procedure.
Oil Cooler
Result: A leak is found in the engine oil cooler.
Repair: Install a new oil cooler. Refer to Disassembly and Assembly, "Engine Oil Cooler - Remove" and Disassembly and Assembly, "Engine Oil Cooler - Install" for the correct procedure.
Flush the cooling system. Refer to the Operation and Maintenance Manual for the correct procedure. Refill the cooling system with the correct coolant. Refer to the Operation and Maintenance Manual for the recommended coolant and capacities.
After the leak has been repaired, refill the engine with oil of the correct specification . Refer to the Operation and Maintenance Manual for the correct oil capacity and viscosity.
Result: A leak was not found in the engine oil cooler.
Proceed to Test Step 2.
2. Cylinder Head Gasket
A. Remove the cylinder head. Refer to Disassembly and Assembly, "Cylinder Head - Remove".
B. Inspect the cylinder head gasket for faults and any signs of leakage.
Cylinder head gasket
Result: The cylinder head gasket does not show signs of damage or leakage.
Repair: Install a new cylinder head gasket and install the cylinder head. Refer to Disassembly and Assembly, "Cylinder Head - Install" .
Result: The cylinder head gasket shows signs of damage or leakage.
Proceed to Test Step 3.
3. Cylinder Head
A. Check for cracks in the cylinder head. Perform a leak test on the cylinder head. Refer to System Operation, Testing and Adjusting, "Cylinder Head - Inspect" for the correct procedure.
Cylinder head
Result: A fault was found in the cylinder head.
Repair: Repair the cylinder head or replace the cylinder head. Install the cylinder head. Refer to Disassembly and Assembly, "Cylinder Head - Install".
Result: A fault was not found in the cylinder head.
Proceed to Test Step 4.
4. Cylinder Block
A. Inspect the top face of the cylinder block for faults and signs of leakage.
Refer to Systems Operation, Testing, and Adjusting, "Cylinder Block - Inspect" for the correct procedure.
Cylinder block
Result: A fault was found in the cylinder block.
Repair: Repair the cylinder block or replace the cylinder block. Inspect the top deck. Refer to the Reuse and Salvage Guidelines for the correct inspection procedure.
Result: No fault was found in the cylinder block.
Install the cylinder head. Refer to Disassembly and Assembly, "Cylinder Head - Install".
Contact the Dealer Solutions Network (DSN).