98423A 8 Mercruiser WIRING HARNESS (228/230/260)

Probable Causes
Engine Oil Cooler
Power Train Oil Cooler (if equipped)
Water-Cooled Turbocharger
Cylinder Head Gasket
BlockRecommended Actions
Table 1
Troubleshooting Test Steps Values Results
1. Check for Leaks in the Engine Oil Cooler
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.
Repair: Install a new oil cooler core.
1. 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.
2. Check the oil for coolant.
Repair: 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. Check for Leaks in the Power Train Oil Cooler
A. Check for leaks in the power train oil cooler. Refer to Testing and Adjusting for the proper procedure
Power Train Cooler
Result: A leak is found in the power train oil cooler.
Repair: Install a new oil cooler core.
1. 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.
2. Check the oil for coolant.
Repair: 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 power train oil cooler.
Proceed to Test Step 3.
3. Inspect the Water-Cooled Turbocharger (if equipped)
A. Inspect the turbocharger for cracks.
B. Remove the oil drain line from the turbo and pressurize the cooling system, Refer to Testing and Adjusting, "Cooling System - Test".
C. Check the turbocharger for coolant leakage.
Turbocharger
Result: The turbocharger is cracked.
Repair: Replace the turbocharger.
1. Flush the cooling system, Refer to the Operation and Maintenance Manual for the correct procedure.
2. Refill the cooling system with the proper coolant. Refer to the Operation and Maintenance Manual for the correct coolant and capacities.
3. Check the oil for coolant. If coolant is found in the oil, drain the oil. Refill the oil after the leak has been repaired. Refer to the Operation and Maintenance Manual for the correct oil capacities.
Result: The turbocharger is not cracked.
Proceed to Test Step 4.
4. Inspect the Cylinder Head Gasket
A. Remove the cylinder head.
B. Check the cylinder liner projection. Refer to the Systems Operation/Testing and Adjusting manual.
C. Install a new cylinder head gasket and new water seals in the spacer plate.
Cylinder Head Gasket
Result: New cylinder head gasket and water seals were installed.
Proceed to Test Step 5.
5. Inspect the 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.
Cylinder Head
Result: A crack is found in the cylinder head.
Repair: Repair the cylinder head and/or replace the cylinder head.
Result: A crack is not found in the cylinder head.
Proceed to Test Step 6.
6. Inspect the Cylinder Block
A. Inspect the cylinder block for cracks.
Cylinder Block
Result: A crack is 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 proper inspection procedure.
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).