Any other way to check head gasket?

[McGary911]

I think there may be a slight chance that I have a bad head gasket. My engine was built when it was a Lake Michigan boat, and i think they may not be marine head gaskets. I may be getting water in #3 under hard running. When i come off the throttle, i develop a miss that clears if i shut down the motor for a minute. I think any moisture water\gas, evaporates off when i do this. I havent checked anything yet (time), but when i do, I may want to verify my head gasket. Sure pulling the head will show me whats up, but is there any other way? Friend suggested compression\leakdown test, but the high pressure air would get past the rings eventually, right? Just looking for some ideas.

[MOP]

Check post #20 in URL below, if you have any questions mail me.

Phil

http://www.donzi.net/forums/showthread.php?t=35243&page=2&pp=15

[rickrsbro]

would the #3 plug be cleaner than the rest if a slight amount of water was getting into that cylinder?

does someone have their party hat on? :happy_bi:

happy birthday !

[MOP]

I know it's your birthday, but I still have to ask:

Your saying a head gasket has to leak into a water jacket, there is no other option??

Sure they do leak other places, but most leaks end up getting into the water jacket. If it is getting into the water jacket that test works.

Phil

[McGary911]

Update! Scott, i checked the plugs and didnt like what i saw on 2 of them. I contacted the guy who originally built the motor in Michigan, and asked him if there were marine head gaskets in the thing. I figure he may not have bothered since it was gonna be a fresh water boat. He didnt have a very encouraging answer for me (maybe).

I pulled the injection, intake, exhaust and the heads. Automotive :mad: I already have all my gaskets to put it back together including some fel pro MARINE head gaskets. Everything looks ok inside. As i dug into it as soon as i had suspicion that something was wrong. Should have it back together by tomorrow, and fired by the afternoon. I feel a LOT better knowing that i found the cause of my woes.

I'll let everyone know how it turns out.

MOP, i didnt use your bubble method, but passed it on to a friend who needs to check his gaskets too. thanks.

[Cuda]

Could you tell it was leaking from the head gasket, or did you just assume it was being an automotive type?

[Cuda]

Just as a side note, I consider low compression or leak down test more likely to indicate valve trouble than any thing else. In other words, because of a bad leak down, the head gasket wouldn't be the first thing I would think is the problem.

[McGary911]

Cuda, I could easily tell by looking at the gasket. Saw the telltale trail from the water passage from the leak. I saw it on the plugs beforehand. Motor only has about 65 hours, about 35 in my salt, and thats about when auto gaskets will fail in the salinity of my ocean\bays here in jersey. Everything else looks perfect, valves, pistons and cylinders, which is a good thing. I already cleaned up 1 head with a scotchbrite pad on a pneumatic drill, and will hit the other one in the am, as well as my intake and block. The thing should purr like a kitten when im done. I cant wait to run it Saturday. Just because my miss last time out bummed me out so much. But now i have the culprit :)

Go figure, i'm actually happy that i have a blown head gasket??? LOL

[Cuda]

While you have the heads off, I'd put a straightedge to them and check they are flat.

Yeah, I'd be happy too, there are a lot worse things it could have been. Good luck with it.

[McGary911]

While you have the heads off, I'd put a straightedge to them and check they are flat.

Yeah, I'd be happy too, there are a lot worse things it could have been. Good luck with it.
My friend's machine shop is 4 miles away, and i already put them on his granite straight edge table, or whatever he calls it. Super flat. Just another reason why I'm happy. ;)

[Cuda]

Good deal. Did you check the block too?

[McGary911]

Engine is all back together! Water tested it Yesterday, and after an initial problem (hose blew off thermostat :rolleyes: and got everything wet), it ran like a champ. I'm happy as hell right now. Only problem is an exhaust leak. I think some of the salt that was blowing out of the cylinder ate away at the aluminum on my exhaust. I can either double gasket it, or drag it over to my friend's machine shop, and mill about 1/8 " off the flanges. Plenty of metal to do that. That's nothing compared what i've just been through.....did i mention that i'm happy I'm running again? :)

[BUIZILLA]

.125 of metal is a BUNCH to mill off, ya might wanta consider maybe .015 to .020 cut instead..

JH :cool:

[McGary911]

.125 of metal is a BUNCH to mill off, ya might wanta consider maybe .015 to .020 cut instead..

JH :cool:

If I had to take off that much, there is enough metal to go that deep, if i had to. I'm sure it would take a bunch of passes. What we will basically do, is take off a bit at a time, until we get through the damaged part of the flange. We did this last year with the risers and exhaust manifold on my big boat. Granted, im not the machinist, my friend is. I just supply the broken part and the beer, he does the rest :beer: