So, I've done the head gasket on one of the notorious 2.2d engines. Then, after some miles it broke down outside the MOT station. Stripped it down and found a snapped camshaft. Every one of the cam carriers has an oil channel, except from the one where it broke. Is this something Toyota designed, should the head have been a reject in quality control, or is it the outside possibility that the cam melted the head and perfectly sealed over the oil port?
TIA, probably also speak to Toyota before going any further