- Leaks in the cooling system
- Leaks in the core of oil cooler
- Leaks in the cylinder head gasket
- Damaged water seals
- Cracks in the cylinder head
- Cracks in a cylinder liner
- Cracks in the cylinder block
- Inspect the water pump for blockage.
Pressurize the cooling system. Refer to Systems Operation/Testing and Adjusting, "Cooling System - Test". If the test indicates a drop in pressure and no outside leaks are detected in the cooling system, there may be an internal leak. Make any repairs, as required.
Check for leaks in the oil cooler core.
Inspect the cylinder head gasket for leaks.
Inspect the water seal for damage.
Check for cracks in the cylinder head. If a crack is found, repair the cylinder head and/or replace the cylinder head.
Check for cracked cylinder liners. Replace any cracked cylinder liners.
Inspect the cylinder block for cracks. If a crack is found, repair the cylinder block or replace the cylinder block.
Check the weep hole in the water pump for blockage. Check the water pump seals for leakage.