do a compresson test i found out that No. 1 bore whose worn out < i made my comp tester out of old glow plug, hose ,500psi tank gauge>ended up fitting bigger 1500 diesel total cost with second hand engine £285 (if head gasket is gone look in bottom of air box for oil/diesel )this happens when one piston acts like a pump and pushes oil up the inlet
shaneg 34/kent, November 2005