So I had this Oliver 1655 apart, I did put a new thermostat in it since it was missing. This tractor is a diesel and so far I've completely redone the head, and it has new injectors. When I first got the tractor It would smoke pretty bad, and around the 2nd cylinder on the onside of the head the tractor will bubble around the head gasket. I think what is bubbling is diesel, it is more clear looking not like oil. I believe I have a compression leak and not an oil or water leak since oil and coolant has stayed the same level while running. Has anyone ran across this problem on 1655 diesels or common problems that could be associated with it. Thanks