31640 4 Mercruiser TRIM TAB (1.98:1 Ratio Only)

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Note: The procedures have been listed in order of probability. Complete the following procedures in the order that is provided.Verify the presence of oil in the coolant with a scheduled oil sample. Verification must be made before following the procedure.
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. If a leak is found, install a new oil cooler core. Refer to the Disassembly and Assembly manual.
B. 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.
C. 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.
Engine Oil Cooler
Result: There is a leak in the engine oil cooler.
Repair: Repair or replace the engine oil cooler.
Result: There is no leak 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. If a leak is found, install a new oil cooler. Refer to the Disassembly and Assembly manual.
B. 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.
Power Train Oil Cooler
Result: There is a leak in the power train oil cooler.
Repair: Repair or replace the power train oil cooler.
Result: There is no leak in the power train oil cooler.
Proceed to Test Step 3.
3. Check for Cylinder Head Gasket Leaks
A. Remove the cylinder head. Refer to the Disassembly and Assembly manual.
B. Check the cylinder liner projection. Refer to the Systems Operation/Testing and Adjusting manual.
Cylinder Head Gasket
Result: There is a leak in the cylinder head gasket.
Repair: 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 leaking.
Proceed to Test Step 4.
4. Check for Cracks in the Cylinder Head
A. Check for cracks in the cylinder head. Perform a leak test on the cylinder head. Refer to Systems 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: Repair the cylinder head and/or replace the cylinder head. Refer to the Disassembly and Assembly manual.
Result: No cracks were found in the cylinder head.
Proceed to Test Step 5.
5. Check for Cracked Cylinder Liners
Cylinder Liners
Result: The cylinder liners have cracks in them.
Repair: Replace any cracked cylinder liners. Refer to the Disassembly and Assembly manual. Check the liner projections. Refer to Systems Operation/Testing and Adjusting for the proper liner projections.
Result: The cylinder liners are not cracked.
Proceed to Test Step 6.
6. Inspect the Cylinder Block for Cracks
Cylinder Block
Result: The cylinder block is cracked.
Repair: repair the cylinder block or replace the cylinder block. Inspect the deck of the engine. Refer to the Reuse and Salvage Guidelines for the proper inspection procedure.