7.4 crusader motor losing antifreeze

[jclark003]

heat exchanger is a another likely cause. when the head gasket fails you typically will see bubbles in the coolant tank when engine is running. make sure not to remove cap when engine is warm however. If oil is clean and no bubbles I would suspect the HEX. Or, not sure about your engine but on some, riser can also cause coolant leaks into exhaust.