5.7 water in #7 cylinder....

[semo549]

I have a 1992 Celebrity 290 with twin 350's. I started having problems with the starter making an awful noise. Found out there was water in #7 cylinder on the port engine. I figured the motor must have diesiled for a second. No big deal, so I keep having the same problem with the starter so I pull the spark plugs and crank the motor over, small amounts of water consistantly spray out of #7 cylinder. I guess I have a cracked head or head gasket. I don't think it's the block because there's not a whole lot of water.

Anyways I pulled the port engine out to diagnose the problem further. I haven't had time to tear the engine apart because of work. So now for the question.... Last night I was talking to the mechanic at my marina, he was telling me if I just repair leak, since there was water in the motor, it will prolly blow within a month or so. So have any of you had a problem like this? Have you made proper repairs and continue to have life out of your engine? If were a gasket I would replace both sides while I have it out. So what do you think the longivity would be if I repaired it and a compression test checks out okay? I will post updates as I get the engine torn down. Thanks for the help guys.

Jim

 

[Bondo]

Re: 5.7 water in #7 cylinder....

Ayuh,... I fix motors everyday that keep Runnin'....

I'd be lookin' at the exhaust manifolds, rather than the motor for that Leak....

 

[semo549]

Re: 5.7 water in #7 cylinder....

Can manifolds go bad over a summers use? we have put 10 hours on it this summer with no issues.. I just figured since it was cylinder specific it must be a head or gasket. Thanks for the reply

 

[Brentathon]

Re: 5.7 water in #7 cylinder....

I had an issue where the pipe plug on the top of my manifold was interfering with the new elbow.....and the elbow wasn't totally sealing to the manifold.
Luckily, the gap was so big that I saw water leaking out from the gasket area.
But I wondered if the gap was small, and on the internal side, i could have continued to leak water back into the manifold....

 

[Philster]

Re: 5.7 water in #7 cylinder....

Same dilemma right now for me. Head or head gasket is most likely. In my case, it's salt water, so there is a major emphasis on compression/leakdown checks before spending bucks on repairs. You don't have salt, but you need to be concerned about internal engine damage.

Don't leave the engine wet. Dry it and oil it (fogging oil or Marvel Mystery Oil).

You have a few days (or less) with fresh water. I had less than 24 hours to get her clean/dry with salt water.

 

[6meter]

Re: 5.7 water in #7 cylinder....

The biggest question is what is leaking? That will determine the repair procedure. Done right, it will last.

 

[rbh]

Re: 5.7 water in #7 cylinder....

Just had to redo the riser gasket because it also leaked back to the last cylinder.
Nuts were not torqued down good enough, they were finger tight. 25ftp I believe is whats called for

 

[semo549]

Re: 5.7 water in #7 cylinder....

Alrighty I pulled the engine apart today and I haven't been able to find the water leak anywhere. The water is also getting into the two ajacent cylinders as well (So now its the back three).

I've checked:
manifold with acetone
Head/riser gaskets are good
no visible cracks in head

The head is being tested by a shop monday morning to verify. Does anyone else have any suggestions of where the water could be coming from?
thanks

 

[NHGuy]

Re: 5.7 water in #7 cylinder....

It sure sounds like the exhaust manifold. You say you acetone'd it. Merc says block off the ports, apply 40psi of air and dunk, try that. I don't see why it should tell you any more than acetone, but that's what the book says.
There is also a possibility that you got the water in the other holes by not draining the cooling system before disassembling. Mercruiser specifically states to drain the manifolds & risers before disassembly to avoid that problem. If you unbolted the manifolds while they contained water they could have wet the other combustion chambers through open exhaust valves. But if the manifold has a water leak it can get into any exhaust valve.
Also check that your exhaust flappers work, they stop water coming up the exhaust when you back off power quick. And does the engine run-on (diesel) when you cut the ignition? That can theoretically cause exhaust water to suck back into the motor.

 

[barterman]

Re: 5.7 water in #7 cylinder....

I have a 1982 SeaRay 260 Sundancer, 260 Mercruier 5.7. Replaced both upper exhaust bellows (rubber). Used aftermarket elbow base gaskets on both sides. Now, I am getting water into the port side last 3 cylinders. Did notice upon installation, that I was getting tiny external leak on external port side elbow. We ran the engine to operating temp, then re-torqued, and got it to stop leaking (externally). Now, with water getting into the last 3 cylinders on the same side, I believe its gotta be more than a coincidence that on this same side, i am getting water into the cylinders. Today, I got some factory
Mercruiser gaskets that seem to be thicker & stronger. Will pull that elbow in the next day or so & install new gaskets & see if that will fix the problem.

 

[semo549]

Re: 5.7 water in #7 cylinder....

Got the head back today, It's cracked. I'm just going to buy a long block. Anyone got a good place to buy motors? Cheapest I've found so far is $2,100

 

[Johnny Be Cool]

Re: 5.7 water in #7 cylinder....

RapidoMarine.com
I think 1500 for a 350 longblock, 200 with shipping.

 

[ibrnrbr]

Re: 5.7 water in #7 cylinder....

Yeah i would check the manifold, riser and gaskets first

 

[semo549]

Re: 5.7 water in #7 cylinder....

RapidoMarine.com
I think 1500 for a 350 longblock, 200 with shipping.

I just checked that website out, they got it for $1600 shipped. That's sounds much better than $2100. Thanks for the help!!!

 

[erikgreen]

Re: 5.7 water in #7 cylinder....

Another vote for Rapido here, good folks. I'm still running the long block I got from them, no problems.