1988 aq131d motor ran hot last year when on plane (did not let overheat) just finished cleaning all of cooling system. started motor and it ran well when i shut it off i noticed anti freeze coming from exhaust (o/d is off the boat) over the next day all of the anti freeze leaked into the exhaust manifold. the heat exchanger is not leaking; new anti freeze added after the thermostat closed remains in the heat exchanger. There is no water in the oil and there is no oil in the water. Blown head gasket ?? Has anyone had this problem if so what was your solution. I started looking at new parts a net head is over 3,000 dollars that is almost what the boat is worth.