BIT-END 4T8089 - Caterpillar

Use this procedure to troubleshoot oil in the coolant.Probable Causes
Water pump
Engine oil cooler
Cylinder head gasket
Cylinder head
Cylinder liner
Cylinder blockNote: 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. Inspect the Water Pump
A. Check for leaks around the seal of the water pump.
B. Inspect the following for damage:
- Seal
- Impeller shaft
- Impeller shaft bearings
Leaks or Damage
Result: The water pump is OK.
Proceed to Test Step 2.
Result: The water pump is NOT OK.
Repair: Perform the following:
1. If a continuous drip is found coming from the water pump weep hole when the engine is off, or a constant stream when the engine is running, replace the water pump shaft seals or replace the pump.
Note: An intermittent drip coming from the weep hole is an acceptable amount of leakage. Intermittent dripping can start and stop throughout the life of the pump, and is a normal part of the operation of the pump.
Wetness or discoloration as a result of dried coolant around the weep hole, without the presence of a continuous drip or a constant stream, is typically another indication of intermittent dripping that is part of the normal operation of the pump. If you are also experiencing low coolant levels, or having to top off coolant frequently, and there is no other source for system coolant loss, replace the pump.
2. Repair or replace the damaged components. Refer to the Disassembly and Assembly manual for additional information.
3. Flush the cooling system. Refer to the Operation and Maintenance Manual for additional information.
4. Refill the cooling system with the proper coolant. Refer to the Operation and Maintenance Manual for the correct coolant and capacities.
5. Check the oil for coolant. If coolant is found in the oil, drain the crankcase.
6. Refill the crankcase with the proper oil after the leak has been repaired. Install new engine oil filters. Refer to the Operation and Maintenance Manual for the correct oil capacities and viscosity.
If the problem is not resolved, proceed to Test Step 2.
2. Check for Leaks in the Engine Oil Cooler
A. Refer to the Reuse and Salvage Guidelines, REHS1758 for additional information.
Leaks
Result: A leak was not found in the engine oil cooler.
Proceed to Test Step 3.
Result: A leak is found in the engine oil cooler.
Repair: Perform the following:
1. Install a new oil cooler core. Refer to the Disassembly and Assembly manual for additional information.
2. Flush the cooling system. Refer to the Operation and Maintenance Manual for additional information.
3. Refill the cooling system with the proper coolant. Refer to the Operation and Maintenance Manual for the correct coolant and capacities.
4. Check the oil for coolant. If coolant is found in the oil, drain the crankcase.
5. Refill the crankcase with the proper oil after the leak has been repaired. Install new engine oil filters. Refer to the Operation and Maintenance Manual for the correct oil capacities and viscosity.
If the problem is not resolved, proceed to Test Step 3.
3. Inspect the Cylinder Head Gasket