Mercruiser 140 water leak

[Al Bell]

I have a mercruiser 140 that just developed a water leak between the manifold and the engine block. It appears that the gasket may have gone bad. Although I am very handy, I called the mechanic to verify my suspicion and he said that yes it was probvably the gasket but there could be something else wrong. Now my question is , Is he just telling me this to get my business and dicourage me from doing the work or are there a host of other problems that can be wrong?

The motor runs fine and is not overheating. I would imagine that it could only be two things, the gasket or cracked manifold.

 

[Bondo]

Re: Mercruiser 140 water leak

I have a mercruiser 140 that just developed a water leak between the manifold and the engine block. It appears that the gasket may have gone bad.

Ayuh,... Keep Looking,... That gasket does Not hold back any water passages....

 

[Al Bell]

Re: Mercruiser 140 water leak

It appears that the water is coming from the seam between the engine block and the manifold. I guess what Bond-O is telling me is that I have a cracked manifold? The water leak does increase as I accelerate the engine.

 

[Bondo]

Re: Mercruiser 140 water leak

I guess what Bond-O is telling me is that I have a cracked manifold?

Ayuh,... That's Not what I said,.. though it maybe True...
The gasket between the intake/ exhaust Manifold,+ the Head, of a 3.0l motor has No wet with water surfaces...
It only seperates the intake air charge,+ the exhaust gases from the outside world,+ each other....
No Water There...
But, both the manifold,+ the Head, as well as the Block, have water passages...
And, the Block is Under the Head, which is what the manifolds are bolted too...

 

[Al Bell]

Re: Mercruiser 140 water leak

Thanks for the input!

 

[Al Bell]

Re: Mercruiser 140 water leak

For future inquiring minds:

The problem was a small hole in one of the FREEZE PLUGS on the cylinder head. The freeze plugs are located on the Manifold side thus making it appear like it is coming from the manifold.

 

[Bondo]

Re: Mercruiser 140 water leak

For future inquiring minds:

Ayuh,.. Thank you Al,...
It'd be Great if more folks would come back to post the Results of the problems they have...
It makes the archives So much more Helpful...

Those Coreplugs are somethin' else,....
A .25 cent piece that takes an overhaul to find sometimes...
There's a couple more Coreplugs between the block,+ flywheel on those motors,...
Was it Rusted through,..?? Is this a Saltwater motor,..??

 

[Al Bell]

Re: Mercruiser 140 water leak

Unfortunately, I made it a salt water boat this summer when I bought. It came from Michigan and I guess this is the way a boat tells you its not happy. I am in the process of reinstalling the cylinder head and would like to know if you or anyone else could advise me the required torque pounds for the cylinder head bolts.

 

[Bondo]

Re: Mercruiser 140 water leak

Ayuh,... As noted in your other thread,...
The factory Manuals are available in the Adults Only section of this forum...