Probable Causes
- Failure of the engine oil cooler
- Failure of cylinder head gasket
- Crack or defect in cylinder head
- Crack or defect in cylinder block
- Failure of the seal between the cylinder head and the sleeve in the unit injector bore
Recommended Repairs
Failure of the Engine Oil Cooler
Install a new engine oil cooler. Drain the crankcase and refill the crankcase with clean lubricant. Install new oil filter elements.
Failure of the Cylinder Head Gasket
Check the cylinder head gasket. Start the engine and remove the radiator cap. Look for air bubbles in the coolant. Air bubbles are an indication of a faulty cylinder head gasket. Replace the cylinder head gasket, if necessary.
Crack or Defect in the Cylinder Head
Install a new cylinder head.
Crack or Defect in the Cylinder Block
Install a new cylinder block.
Seal Failure
Replace the sleeve. Refer to Special Instruction, SEHS9120, "Using the 127-3458 Sleeve Replacement Tool" for information on replacing unit injector sleeves.