75 horse Mariner spraying water from strange place

[starkyb]

I was running my 75 horse Mariner and water was spraying from a small hole from the top of the engine right next to the top spark plug. The hole is in the middle of a raised round part on the back of the engine. The hole is about the size of a finish nail hole and the water stream is very steady. Can anybody tell me what the reason for this is? Thanks for your response!!!

 

[saumon]

Re: 75 horse Mariner spraying water from strange place

I'm not sure, we'll need a pic and the year of your engine (3 or 4 cylinders?), but it could be a defective popet valve and water exit through the little pressure relief hole on top of the t-stat/poppet valve cover...

 

[Faztbullet]

Re: 75 horse Mariner spraying water from strange place

Sound like a inline 4 cylinder and water jacket cover gasket is bad.. bet if you look really close you will see gasket pooched....

 

[starkyb]

Re: 75 horse Mariner spraying water from strange place

The year is 1988 and it is a 3 cylinder. Is that a pretty easy fix for somebody mechanically inclined?

 

[starkyb]

Re: 75 horse Mariner spraying water from strange place

It is a 1988 3 cylinder. Lets just assume the gasket is bad. If so could water get into the spark plug and cause the engine to run rough and sometimes cut off. If so that could address another problem I have been having. That would be great to kill two birds with one stone or catch two fish on one cast since I am also a bird watcher also ha ha ha!!!

 

[cr2k]

Re: 75 horse Mariner spraying water from strange place

I agree with faztbullet. No it is a simple job IF you get the bolts out without twisting them off. I would try them gently then soak them with PB Blaster or simular. You may have to use heat. Then it's just pull the cover off, clean the surfaces, dope up a new gasket (permatex avaition gasket sealer) and replace. Easy on the torque (don't know the specs off hand) they are small bolts in aluminum. Just use a 1/4 in drive ratchet (not a long handle) and go easy.

 

[starkyb]

Re: 75 horse Mariner spraying water from strange place

That sounds pretty simple. Do you know if a bad gasket could cause a cylinder to misfire which would cause gas to leak out and the engine to cut off?

 

[ajgraz]

Re: 75 horse Mariner spraying water from strange place

The water jacket gasket leak you have happens to virtually all the 3 cyl Mercs eventually. That leak is not causing water to go into the cylinder, though you should do a compression test to make sure there isn't a breach in the cylinder wall that may cause water intrusion.

A quick fix is to slap some RTV silicone on the hole. That'll keep water from spraying inside the cowling until you can look into replacing the gasket.