6984M Mariner SHAFT, CRANK

Recommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in the order of the listed test steps.
Table 1
Troubleshooting Test Steps Values Results
1. Check for Leaks in Engine Oil Cooler Core
Cooler
Result: A leak was not found.
Proceed to the next step.
Result: A leak was found.
Repair: Install a new oil cooler core.
Drain the crankcase and refill the crankcase with clean engine oil.
Install new engine oil filters. Refer to the Operation and Maintenance Manual.
If the problem is not resolved, proceed to the next step.
2. Check the Jacket Water Pump
A. Check the weep hole of the jacket water pump for plugging. A plugged weep hole may cause coolant to be forced past the pump shaft seals into the crankcase.
B. Thoroughly inspect the water pump for damage and cracks. If internal leakage is suspected, remove the pump from the engine in order to perform a thorough inspection.
Pump
Result: The weep hole was not plugged and the pump is not damaged.
Proceed to the next step.
Result: The weep hole was plugged.
Repair: Clear the plug.
Result: The pump is damaged.
Repair: Repair the pump or install a new pump.
If the problem is not resolved, proceed to the next step.
3. Check the Auxiliary Water Pump (If Equipped)
A. Check the weep hole of the auxiliary water pump for plugging. A plugged weep hole may cause coolant to be forced past the pump shaft seals into the crankcase.
B. Thoroughly inspect the water pump for damage and cracks. If internal leakage is suspected, remove the pump from the engine in order to perform a thorough inspection.
Pump
Result: The weep hole was not plugged and the pump is not damaged.
Proceed to the next step.
Result: The weep hole was plugged.
Repair: Clear the plug.
Result: The pump is damaged.
Repair: Repair the pump or install a new pump.
If the problem is not resolved, proceed to the next step.
4. Check the Water-Cooled Turbocharger (If Equipped)
A. Pressurize the cooling system and thoroughly inspect each of the turbochargers for external leakage and internal leakage.
Turbocharger
Result: The turbochargers does not leak.
Proceed to the next step.
Result: The turbochargers does leak.
Repair: Perform the necessary repairs.
If the problem is not resolved, proceed to the next step.
5. Check for leaks in the Cylinder Head Gaskets
Gasket
Result: None of the gaskets are leaking.
Proceed to the next step.
Result: A gasket is leaking.
Repair: Install a new cylinder head gasket and new water seals in the spacer plate.
If the problem is not resolved, proceed to the next step.
6. Check if a Cylinder Head is leaking due to a Crack
Head
Result: None of the heads are cracked.
Proceed to the next step.
Result: A head is cracked.
Repair: Install a new cylinder head.
If the problem is not resolved, proceed to the next step.
7. Check if a Cylinder Liner is Leaking due to a Crack
Liner
Result: None of the liners are cracked.
Proceed to the next step.
Result: A liner is cracked.
Repair: Install a new cylinder liner.
If the problem is not resolved, proceed to the next step.
8. Check if the Block is Leaking due to a Crack
Block
Result: The block is cracked.
Repair: Repair the cylinder block or replace the cylinder block.