Symptoms of water jacket leak?

[MercMan82]

I rebuilt my 1150 and cleaned all the surfaces very well. I used gasket sealer with new gaskets on all covers. I found a few bolts on the exhaust plate and cylinder block cover trickling water which I'm not too worried about. I'll torque those in and see what happens. However, I am worried that if those are leaking, then possibly the water jacket is leaking. What are the symptoms of a leaking water jacket and should I pull the cover to visually check after I run it next time to be sure?

 

[MercMan82]

Re: Symptoms of water jacket leak?

Just read that white smoke out the exhaust is a sign, and I remember it running for a few without smoke then it started smoking good and when I stood behind it, my leg was soaked by water vapor. I thought maybe it was getting water in the exhaust tube from the water pouring in but it's starting to add up now. Better check it to be sure.

 

[Texasmark]

Re: Symptoms of water jacket leak?

The biggest sign (in my opinion) of having water in a cylinder is either visual presence of water in whatever form, or one cylinder that is spanking clean when the others show carbon deposits.

Smoke out the exhaust and mist/spray/dribbling water out of the prop are all normal conditions.

HTH,

Mark

 

[MercMan82]

Re: Symptoms of water jacket leak?

Hmm, I'm gonna pull the plugs and look them over good. Then just for my piece of mind, gona pull the cover. I did too much to take a chance. Will water in the cylinder Cause the idle to stumble?

 

[Texasmark]

Re: Symptoms of water jacket leak?

Hmm, I'm gonna pull the plugs and look them over good. Then just for my piece of mind, gona pull the cover. I did too much to take a chance. Will water in the cylinder Cause the idle to stumble?

Yes. If you have some time on it since you worked on it, look at the crown of the piston. If watered, it will be much cleaner than the other pistons even if water is not physically present (viewable). If you ran it often enough there wouldn't be any cylinder rust on the cylinder walls. If not expect to see rust on that cylinder.

Butttttttttt What water jacket are you talking about? A lot of Mercs don't have head gaskets; just water jacket covers over the head which is an integral part of the block......you won't get water into the combustion chamber from that cover/gasket. On the exhaust cover, there is a combustion chamber seal, cover plate, water jacket seal and water jacket cover plate. Even that one would be hard to get water into the combustion chamber and if you did it would primarily affect the lower cylinder and the entrance of the would leave tell tale marks easily troubleshot.

Mark

 

[MercMan82]

Re: Symptoms of water jacket leak?

Interesting, it stumbled a few times but not consistently or enough that I knew there was water in there.

 

[Texasmark]

Re: Symptoms of water jacket leak?

Interesting, it stumbled a few times but not consistently or enough that I knew there was water in there.

Let's back the truck up. What engine do you have?

 

[MercMan82]

Re: Symptoms of water jacket leak?

Lol, oh yeah, you don't know that do you? 1971 1150

 

[Texasmark]

Re: Symptoms of water jacket leak?

Lol, oh yeah, you don't know that do you? 1971 1150

Great. You don't have a problem! Head is integral to the block casting.

Mark

 

[MercMan82]

Re: Symptoms of water jacket leak?

It's an inline 6. The water jacket is what I'm worried about. It's below the deflector plate.

 

[Texasmark]

Re: Symptoms of water jacket leak?

It's an inline 6. The water jacket is what I'm worried about. It's below the deflector plate.

I had the '89 115 tower for 7 years that I bought new in '89. Had one problem over the years and it was a leak develop along the outer edge of the water jacket cover over the heads (spark plug holes in it). I replaced it just as I said to do and had no further problems. Son-in-law still has it and has had no further problems.....

HTH,

Mark

 

[MercMan82]

Re: Symptoms of water jacket leak?

I think we're talking about different covers. The cylinder block cover(the one I think you're talking about) and the water jacket cover(the cover underneath the exhaust cover and deflector plate.

 

[Texasmark]

Re: Symptoms of water jacket leak?

I think we're talking about different covers. The cylinder block cover(the one I think you're talking about) and the water jacket cover(the cover underneath the exhaust cover and deflector plate.

Yes we are. Follow your instincts. I agree.

Mark

 

[MercMan82]

Re: Symptoms of water jacket leak?

Thanks man. I appreciate you talking it out with me. I am gonna pull that cover and redo the gasket.

 

[Faztbullet]

Re: Symptoms of water jacket leak?

Install a set of non S/S spark plugs and run it. Check them the next morning and if you have any water it will show up as rust on the plug and piston will be steamcleaned. The exhaust deflector plate need to be installed dry with no sealers and the bolts resiweld in place.

 

[MercMan82]

Re: Symptoms of water jacket leak?

I'm a little nervous of hydro lock. I guess if I take the plugs out and turn it over a few times put the plugs and crank it, it should be fine. Why install deflector plate dry?

 

[Faztbullet]

Re: Symptoms of water jacket leak?

Why install deflector plate dry?

Service school taught that any silicon based sealer could cause a leakage and most silicons wont hold up to heat in this area anyway,that why resiweld is called for instead of loctite on bolts as it good to about 400?

 

[MercMan82]

Re: Symptoms of water jacket leak?

Service school taught that any silicon based sealer could cause a leakage and most silicons wont hold up to heat in this area anyway,that why resiweld is called for instead of loctite on bolts as it good to about 400?

I seem to have proved them right about it leaking then. You mentioned the deflector plate dry but what about the water jacket? Also, is resiweld a common product or marine stores only?

 

[Texasmark]

Re: Symptoms of water jacket leak?

Service school taught that any silicon based sealer could cause a leakage and most silicons wont hold up to heat in this area anyway,that why resiweld is called for instead of loctite on bolts as it good to about 400?

I just went out to the shop and got a new tube of Permatex Blue RTV Silicone "Gasket Maker" it's called. On the rear of the package it comes in it says "Temperature range: -65F to 500F". That ought to cover it.

But really man, you are talking about a rather thin aluminum (3rd best heat/cooling/electric current conductor) that has exhaust on one side and 140 to 190F (worst case) water on the other. It ain't a gonna see any 400F...maybe 200 and that's a walk in the park.

I don't have any of that stuff you called for but I do have 3 different grades of Locktite, including blue #220 for removable fastners and I also have a couple little packets of Thread-Magic Anti-Seize that they sell for your spark plug threads at the auto parts store...(where I got the RTV). On the package it says it is also used for "Head Bolts, Alternator Bolts, Starter Bolts, Water Pump bolts". The screws are screwed into the block and it too MAY see 200F. That ought to cover it.

Looks like we are good to go. I guess Merc Man can make up his own mind. We did what we can do for him.

Mark

 

[MercMan82]

Re: Symptoms of water jacket leak?

Lol, well, I used some gasket sealer on the jacket and deflector plate. What I'm gonna do to save me some time, I'm gonna clean the surfaces and gaskets best i can. Then put some rtv on to help seal cause of the old gasket sealer that will be scrapped off. I agree with you on the blue loctite texasmark. If it gets hot enough to loosen the loctite, I think that it will be the least of my problems and I have some already. Thanks guys. I think both ways are correct, but you can't do both.