GEAR-SUN 6Y0061 - Caterpillar

Probable Causes
Engine oil cooler core
Cylinder head gasket
Cylinder head
Cylinder liner
Cylinder blockThe procedures have been listed in order of probability. Complete the procedures in order.Verify the presence of oil in the coolant with a scheduled oil sample. Verification must be made before performing the procedure.Recommended Actions
Table 1
Troubleshooting Test Steps Values Results
1. Engine Oil Cooler Core
A. Check for leaks in the engine oil cooler. Refer to Testing and Adjusting for the proper procedure.
Oil cooler
Result: A leak is found in the engine oil cooler.
Install a new oil cooler core. Refer to the Disassembly and Assembly manual.
Flush the cooling system. Refer to the Operation and Maintenance Manual for the proper flushing procedure. Refill the cooling system with the proper coolant. Refer to the Operation and Maintenance Manual for the correct coolant and capacities.
Check the oil for coolant. If coolant is found in the oil, drain the crankcase. Refill the crankcase with the proper oil after the leak has been repaired. Refer to the Operation and Maintenance Manual for the correct oil capacities 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, and check for cracks or damage to the cylinder head gasket. Refer to the Disassembly and Assembly manual.
Cylinder head gasket
Result: The cylinder head gasket is cracked or damaged.
Install a new cylinder head gasket and new water seals in the spacer plate. Refer to the Disassembly and Assembly manual.
Result: The cylinder head gasket is NOT cracked or damaged.
Proceed to Test Step 3.
3. Cylinder Liner
A. Check for cracked cylinder liners. Replace any cracked cylinder liners. Refer to the Disassembly and Assembly manual.
B. Check the cylinder liner projection. Refer to the Systems Operation/Testing and Adjusting manual.
Cylinder liner
Result: A crack is found in the cylinder liner and/or liners.
Make the necessary repairs. Verify that the problem is resolved.
Result: A crack is not found in the cylinder head and/or liners.
Proceed to Test Step 4.
4. 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 for the proper procedure for checking the cylinder head.
Cylinder head
Result: A crack is found in the cylinder head.
Repair the cylinder head and/or replace the cylinder head. Refer to the Disassembly and Assembly manual.
Result: A crack is not found in the cylinder head.
Proceed to Test Step 5.
5. Cylinder Block
A. Inspect the cylinder block for cracks.
Cylinder block
Result: A crack is found in the cylinder block.
Repair the cylinder block or replace the cylinder block. Inspect the top deck. Refer to the Reuse and Salvage Guidelines for the proper inspection procedure.