Mercury 115 1994-95 Leaking water from the thermostat

by steffan thon

I have an Mercury 115 1994-95 it is leaking water from the place the thermostat is, other owner told me it was because water here in the north is so cold. He did connect an rubber hose so the water not got on the spark plugs. he also told that it only leaks when engine was cold, but the engine will never get warm, after 1 hour drive water in the engine is cold. hmmmm i think he did lie to me must be an other prob. i will try to get new thermostat hope this will fix the problem... Any suggestions please help me

Comments for Mercury 115 1994-95 Leaking water from the thermostat

Average Rating starstarstarstarstar

Click here to add your own comments

Jul 07, 2016
leaking from poppet valve
by: steffan

Hello thanks for reply . i have termostat but it is broken. but the water that comes is not from the termostate it is from the popet valve. first i thought it was from the termostate but it is not . so osmething is broken in the popet valve. it comes alot of water so it is a rubbel hose around it so the water leak out from the engine. have the part to fix it but need find someone that can look at it. hope not anything damage inside the poppet valve. and the Engine is 1991 mod not 94-95 seller lied to me :(

Apr 18, 2016
water leaking fro thermostat housing merc 94 black max
by: Anonymous

had the same issue here is how to fix,remove housing mine had pitting from corrosion clean the base and or sand the housing and the area in the where it seats as to make both surfaces as smooth as possible make a template w the housing onto a piece of gasket material from your local auto parts store place gasket on to the surface and use a gasket sealer and presto is done my leaked as well onto the spak plugs 1994 150 black max 900 hrs

Jun 18, 2014
Water leaking from the thermostat housing
by: Bruce

Sounds like you do not have a thermostat for your motor. If you did the water would get hot. When you get a new thermostat fixed that gasket and you won't have a water leak. Check the water hoses and make sure there is no water leaking from them either.
The thermostat is a water restriction allowing the engine to heat the water up in the motor so it can reach operating temperature.
With no thermostat to restrict the waterflow the engine cannot hit the water fast enough because it is constantly being replaced with cold water.
I hope that helped you

Click here to add your own comments

Join in and write your own page! It's easy to do. How? Simply click here to return to Mercury Forum.