Engine Oil in Cooling System

01-87101 Engine Oil In Cooling System Engines 601, 602, 603 10/87

Cause:
Cylinder head porosity in the area of the front oil gallery for the oil supply of the first camshaft bearing and the hydraulic valve tappets.

Remedy:
Replace cylinder head. Clean cooling system.

Note:
This porosity can not always be detected when pressure testing the cylinder head.