Water in # 4 cylinder!!

[birdy3897]

Pulled head off motor and found water in my #4 cylinder head. Oddly enough the head gasket looked good. I also see no noticable cracks in the head or cylinder wall. Any suggestions? Motor is a 2.5L 120hp (1978) mercruiser.

 

[birdy3897]

Re: Water in # 4 cylinder!!

I should add that me brother put the head back on the motor last year and reused the head gasket. I knew this was a no no but it seemed to run fine. Maybe this is the problem?

 

[Don S]

Re: Water in # 4 cylinder!!

Reusing a head gasket belongs in the "Duh" catagory.<br />Keep your brother away from your engine.

 

[birdy3897]

Re: Water in # 4 cylinder!!

I agree, but duh is being nicely put.Could it be caused from using incorrect gaskets at the manifold or riser?

 

[Don S]

Re: Water in # 4 cylinder!!

It could be caused by lots of things. Bad manifold or riser (common) bad gasket between them (common), water coming up the drive and into the manifold due to defective shutters in the Y pipe (since you are probably on a trailer when this all happened, not likely) rain down the carb and the valves are open on #4 (seen it before)<br /><br />But after reusing a head gasket, that would be the very FIRST I would look at and replace.

 

[Boatist]

Re: Water in # 4 cylinder!!

I agree with Don. If this is a Saltwater boat I would check the exhaust manifold and riser very closely. When they leak it always affects Cylinder 4 because water get in the exhaust passage and runs to the lowest cylinder number 4.<br />Head Gaskets are cheap, why take that chance?

 

[birdy3897]

Re: Water in # 4 cylinder!!

How do you actually tell if the manifold or riser are bad? What should I check for? I do remember putting on the riser when I replaced the bellows and the shutter was missing. Would this have caused it? The boat hasn't been in the water yet, just run on the trailer with a test tank. This boat is also just a freshwater run 2.5L.