coolant leak

[sandydog]

Well since we are Carver owners maybe some one in here has had this problem.
My starboard engine does not over heat but loss of coolant after shut down and cool of is a problem.
I have a 2767 1987 Carver santego with the twin 4 cyl mercury engines
closed cooling system
as we cruise no problem or coolant leak but wake up the next morning and all the anti-freeze is in the bildge not in the oil pan or internal so we have checked with pressure tester checked heat exchanger and no steam from exhaust.
I am thinking a seal on the cam shaft inside the water pump and as it cools and contracts it looses pressure and comes out the weeping hole in the bottom of the pump
no hoses leak we replaced them all and checked again
I have sat and watched this thing for hours untill you give up and then low and behold it does it overnight a real gremlin.
Will it be necessaery to lift to engine out and do this repair or does any body have a suggestion
I posted this in the engine form but had no real luck
Your thoughts greatly appreciated my marina says lift engine and get right to the root of the problem of course this is very expensive and I am not confident this is totally necessary
Now I am loosing boating time and frustrated

 

[Unknown]

Just wondering if there's something wrong with one or both radiator caps. The caps help pressurize the system but just like an old car they have a tube that extends from the cap either into a recovery bottle or the bilge floor. On my 1980 Mariner the tubes go right into the bilge. Perhaps yours does, too...

 

[pdecat]

buy a system pressure test tool. You apply pressure and look for leaks, it allows presurizing with everything cold so expansion is not a problem. Unless you have some specific reason to suspect the cam shaft plugs my guess would be something much simpler like a coolant pump. Look at the weep hole under the shaft.