Probable Cause:
1. Failure Of Oil Cooler Core
Install a new core for the oil cooler.
2. Failure Of Cylinder Head Gasket
Install a new cylinder head gasket. Tighten the bolts holding the cylinder head, according to the Specifications.
3. Crack Or Defect In Cylinder Head
Install a new cylinder head.
4. Crack Or Defect In Cylinder Block
Install a new cylinder block.
5. Failure Of Front Cover Gasket
Install a new front cover gasket.