OMC 5.7L Cobra with water in #4 cylinder

[jeremyp111]

I started noticing a loss in power and a rough idle so I checked my plugs and found the #4 plus was wet and carbon fouled. I replaced the riser gaskets last year because I was getting water in the cylinders, but now its only 1 cylinder. I'm assuming that now it has to be a cracked manifold or cracked head. Is there any way to determine this without pulling them off? What will a compression test tell me?<br /><br />Thanks,<br /><br />JP

 

[akriverrat]

Re: OMC 5.7L Cobra with water in #4 cylinder

good compression on all 8 tells you engine probably ok and manifold first place to look. if you have water in that cylinder. the way you describe it, it allmost sounds as tho its wet with gas. usually water cleans carbon out.

 

[jeremyp111]

Re: OMC 5.7L Cobra with water in #4 cylinder

It's definitely wet with water. Put new plug in, power came back for a short time, but started to lose it again. Plug was definitely covered in carbon most likely due to poor combustion in that cylinder because of the water. Also getting hydrolock when trying to start the engine from time to time because of the water. Just need to try to nail down the reason why water is getting in the cylinder.

 

[jeremiah89]

Re: OMC 5.7L Cobra with water in #4 cylinder

It's definitely wet with water. Put new plug in, power came back for a short time, but started to lose it again. Plug was definitely covered in carbon most likely due to poor combustion in that cylinder because of the water. Also getting hydrolock when trying to start the engine from time to time because of the water. Just need to try to nail down the reason why water is getting in the cylinder.

Did you ever figure anything out?