Merc 140 Leaking head gasket

[RaysZ71]

got an '86 with the Mercruiser 140.

on the pushrod side of the block I have water leaking from the head gasket area between Cyl 2 and 3 and behind 4. It bubbles out, not a big stream. I also have water in the oil. I am thinking the head gasket is leaking both internal and external.

any thoughts before I pull the head?

 

[fat fanny]

Re: Merc 140 Leaking head gasket

Possible head gasket but I would look more towards a cracked block. Look closely around the areas that are suspect of the leaks then pull the head.

 

[Don S]

Re: Merc 140 Leaking head gasket

Pull the manifold first.
See if there are cracks in the block about 1/2 to 1" below the head gasket.
External leaks and water in the oil are NEVER caused by a blown head gasket, but always hoped for by the owners.

 

[RaysZ71]

Re: Merc 140 Leaking head gasket

heres an update.

I pressure tested the block yesterday. Heard it leaking.. From the head gasket under the spark plug for the no 3 cylinder.

Today, I pulled the head. Couple of observations..
1. the head bolts seemed to not be torqued down. Not loose, but no where near what i would call tight. Exhaust bolts were the same way.
2. Head gasket was blown between cyl 2 and 3.
3. had a bent pushrod on no 1 cyl.

it appeared that I had some water leakage where i heard the leak, and also looks like it may have leaked into the no 4 cyl.

I have not found any cracks yet, but I will be cleaning up both the head and block this week and check the head for warpage.

Will also be checking that no 4 cyl more thorough, and check the manifold too.