Mariner 150 Water in #6

[Paul Jenkins]

I have a 1987 model Mariner Magnum 150. I am getting water in the #6 cylinder. I replaced the head gasket but that did not fix the problem. I read it could have something to do with the exhaust divider plate or the divider plate gasket. Help if you have ideas on where to look. I did not see evidence of cracking on the head or in the cylinder when I had them off but I may have missed something.

 

[Dukedog]

This.......

I read it could have something to do with the exhaust divider plate or the divider plate gasket. .

Check gaskets and "double check" actual divider piece for any tiny rust holes or cracks. Lay it flat then fill it wit water and let it set for awhile. Sometimes it will show a seepage that ya miss wit tha eye. That seepage grows with heat and pressure.......

 

[Paul Jenkins]

Thank you I will try that.

 

[Paul Jenkins]

Thank you I will try that.

 

[Paul Jenkins]

I pulled the divider plate. I filled with water and did not find evidence of seepage. The gaskets looked ok but there was one bolt on the bottom row that was not as tight as the others. Where else should look for leaks. What do you suggest?

 

[Dukedog]

Head and/or gasket, divider plate and/or gaskets are tha usual culprits and normally leave a tell-tale sign of some kind. Comp on no. six where it should be? Without a visual its a hard call.....

 

[Paul Jenkins]

Compression is the same in all cylinders that i checked. I looked for signs but did not see anything obvious. I am not an expert by any means however. I replaced the head gasket when I first discover the problem by the way it was running. The amount of water is just enough to kill the spark but it runs normal speratically.

 

[Paul Jenkins]

I changed the divider plate gaskets but i am still getting water in the #6 cylinder. Any suggestions on where to go from here?

 

[Dukedog]

We aren't home at tha time and I'm lay'd up with shoulder surgery and memory ain't good enough. Warped heads and/or gaskets. Warped divider pieces and/or gaskets as for as I can remember, other than a crack/hole, are tha only things that that will allow tha water go where its not supposed to. Maybe and I say just maybe a bad power head gasket. Would need to visually look at tha block base and adapter plates ta see if tha same applies to those. Can't think of any place between those parts where warped parts or bad gasket would allow water to transfer. This is where tha memory sucks. Maybe some else on here could tell for sure..........

Just thought of this. Think your motor has tha "two piece" heads. That's another place you could check gaskets/crack. Never seen it happen there but.........
Just be very careful with tha bolts on tha cover. They are more than likely rusted up. Ya might squirt a little PB on 'em then let it set for a day or two before ya start. You will need new gaskets there. Won't be any savin' 'em............

 

[Paul Jenkins]

I had another person mention it may be the lower main bearing and seal. What are you thoughts on that as a possible leak point? I checked the head over pretty close when I had it apart and did not see any sign of cracks. I don't remember if I checked for flatness but if my memory serves me correctly, I did put a straight edge on it and checked it with a feeler gauge.

 

[Dukedog]

Bottom of tha crank is possible just not very common. There are two seals and a sealing ring that it has ta get by with very little pressure in that area but at this point what ya got ta lose............

 

[Paul Jenkins]

Very true. Couple seals and some time. I will give it a try, it's much cheaper than a new or rebuilt block. I will let you know what happens. Hope you get healed up soon.

 

[Paul Jenkins]

I decided not to dive into the lower main seals and went back to the head in stead. A local mechanic agreed with your take on the main seals. In looking at the head I don't see evidence of cracking and I checked to see if it was warped. I used a straight edge an a feeler gauge and it appears flat. I am going to take it to a machine shop to see if they can test it for me. The cylinder looks good as well. Would there be any tell tale signs if it was cracked? Could a crack be below the top of the piston? Thanks again for your help.

 

[Paul Jenkins]

I removed the head, had it measured, tested, and milled. Put it back together and still have water. Had as much of the jug dye checked as possible with it assembled. Went from boat to anchor I am afraid. Thanks for your help.