84 Johnson 155 water leak

[patrch]

I have a water leak at the back of engine. I as wondering could water leak between the power head and the lower leg from the power head gasket, or just from the thermostate inlet cover.

 

[emdsapmgr]

Re: 84 Johnson 155 water leak

That engine can leak water from various sources. The powerhead base gasket or the exhaust manifold cover. Also possible it could leak from the dual thermostat covers, one on each head. These V6's don't usually leak at the powerhead base gasket like the V4 engines historically do, but it's possible. If the base gasket it leaking, you'll have to pull the powerhead, about a 3 hour job for a skilled mechanic.

 

[patrch]

Re: 84 Johnson 115 water leak

Re: 84 Johnson 115 water leak

It's hard to pinpoint but it seems it's comming for the bottom side of the lower cylinder gasket.
Just want to make sure this is possible before I replace that cylinder head gasket. It's not leaking from the thermostac housing or the inlet hose, it's leaking down from under the cylinder head.

 

[emdsapmgr]

Re: 84 Johnson 115 water leak

Re: 84 Johnson 115 water leak

I see you changed the hp of the engine. Makes a difference. I'd be inclined to retorque the head which may be leaking. See what happens. Hopefully, it's just this gasket. Also could be the head cover leaking-a minor problem. The V4 engines do have a history of powerhead gasket failures when they get older. Usually when they fail, however, you will get some nasty exhaust leaks inside the cowling along with some water at the base of the engine. If you have no exhaust leaks, that base gasket may be ok.

 

[patrch]

Re: 84 Johnson 115 water leak

Re: 84 Johnson 115 water leak

Sorry I didn't realize I typed 155. Its a brand new gasket. I had the cylinder heads honed replace 1 piston and all the rings. It started leaking about a week later. Is it possible to retorque the head without pulling the power head. Looks like there's not much room to get at the bottom bolts. What would the torque be?

 

[emdsapmgr]

Re: 84 Johnson 115 water leak

Re: 84 Johnson 115 water leak

If you just overhauled the powerhead, it's a really good idea to retorque the heads after the engine goes through the first couple of heat/cool cycles. Might as well do it now. The head bolts should be torqued to 20 ft. lbs, in an outward circular pattern. Good luck with the leak. I don't pull the powerehead. You should be able to fit a torque wrench on each bolt, if it's either a 1/4" or 3/8" drive wrench and you use normal sockets.

 

[patrch]

Re: 84 Johnson 115 water leak

Re: 84 Johnson 115 water leak

I tried 2 new gaskets and it still leaks in the same area. Could it be the way I apply the gasket sealer. There is no damage to to the surfaces. It never overheated. Could something be warped. It was ok before we had the rings replaced. It leaked a little but they fix it . I didn't last.

 

[emdsapmgr]

Re: 84 Johnson 115 water leak

Re: 84 Johnson 115 water leak

Is the leak from the head gasket area or the cyl head covers?

 

[patrch]

Re: 84 Johnson 155 water leak

It's leaking from the left lower cylinder head Piston # 4 Not the end cap

 

[emdsapmgr]

Re: 84 Johnson 155 water leak

You could pull the head and put if on a flat surface to see if the head face is warped. A special (mechanic's) straight edge would work. Also you could try a pc of plate glass.

 

[patrch]

Re: 84 Johnson 155 water leak

Is it a good idea to use a gasket sealer. Thanks for your inputs.

 

[emdsapmgr]

Re: 84 Johnson 155 water leak

Most of the newer head gaskets say that sealer is not required. The OMC service instructors say that the additional use of gasket sealer does not hurt anything. The gasket for the water jacket cover on the head should be applied with gasket sealer.