1989 merc 350 bravo inboard closed loop cooling overheating and leaking coolant. Not in bilge, spark plugs and oil look good. Doesnt look like its going through the exhaust. Any idea where to look next? Any help or tips appreciated. Dont think its going through head to crankcase but if it does, could it go anywhere else after that? oil level is good and oil isnt murky cloudy or separating.