Stuck on lake today! overheated and locked up!

[fireicyhott]

Well just when I got my 1990 Four Winns 225 Sundowner with 5.8L OMC/Cobra running good this happens.

I have had the boat out several times in the last 2 weeks since I got the points issue corrected. One time in about 8 outings the temp gauge spiked up and I shut the engine off for a bit and then everything was fine.

Well today I was out and the temp gauge was at 150-175 for the whole afternoon (1.5 hrs of start and stop). Then I noticed during a 5 min run of WOT the gauge spiked up to 230 F or so. I shut it down to let it cool.

Well I was sitting there watching the engine while it cooled, making gurling noises from the water being so hot. Then all of a sudden it is as if it BELCHED a big bubble, the motor actually moved. I was like oh ****. I had a bad feeling I had water in the cylinders.

I tried to turn over the motor and it wouldn't budge. Yep, water in cylinders. I proceeded to spend the next hour pulling all 8 plugs, turning motor over to clear pistons of water, and then reinstalling plugs. It fired up and I went to dock. Some questions:

1. Why did it overheat? I have removed and inspected impeller in last 3 weeks, everything looked fine and while running it with muffs it sucks water in and spits it out like it should.

2. Should I go ahead and replace thermostat?

3. What was that belch noise and how does water actually get into combustion chambers?

4. Do I have to change the motor oil now that there is probably water in it?

5. Does anyone know of an easier way or different tool to use to pull those damn plugs? I use a spark plug socket and a 19mm open end wrench as you can't get a socket wrench on it due to angle.

Frustrating weekend as my well went out yesterday too! Hell I am afraid to get off the couch now!

Thanks,

Jeff

 

[Boomyal]

Re: Stuck on lake today! overheated and locked up!

Two possible reasons for water in the cylinder. Cracked head/head gasket or bad exhaust manifolds. I vote for head gaskets. Over heating is a classic symptom.

I would definitely drain the oil then pull the heads.

 

[a70eliminator]

Re: Stuck on lake today! overheated and locked up!

I'm curious, you actually pulled the plugs and found all 8 cylinders full of water, yet was able to fire it up and get back in thats amazing how did it run? Is the oil/water clear up on the dipstick now? I also have a 4 bbl 351 and have been following all your threads, sorry to hear all your bad luck hopefully you just need a new well pump. As far as your boat, I'm by far experienced enough to give advise, but the gurgle and bang was definately water hammer, (thats a term used by pipefitters) it's when water meets steam and results in a violent bang, potentially very dangerous, it can blow pipe apart easily.

 

[fireicyhott]

Don and Haute Medic, what do you think? Re: Stuck on lake today! overheated and

Don and Haute Medic, what do you think? Re: Stuck on lake today! overheated and

Eliminator, haven't had time to check dipstick yet. Made it to dock, ran it slowly, wasn't far, but seemed to run fine! Boat only has 300 hrs on it.

When you say well pump do you mean the rubber impeller or the circulating water pump?

Don and Haute Medic what do you think?

Jeff

 

[wvit1001]

Re: Stuck on lake today! overheated and locked up!

Another case of - " I don't know why the temp gage keeps going up so let's just run it till it explodes. "

 

[fireicyhott]

Re: Stuck on lake today! overheated and locked up!

Wvit,

I appreciate the help with the question.

Actually the gauge has only gone close to hot twice in about 20 times on the lake. I thought maybe the first time was a fluke with everything else I was sorting out on the boat. Never did it again til yesterday. I shut it off as soon as I realized it was definitley getting hot.

Apprreciate the support from Wylie down there.

Jeff

 

[Haut Medoc]

Re: Stuck on lake today! overheated and locked up!

Well, I'm not really an OMC guy, but.....
Sometimes something like a plastic bag or such can cut off water supply....
Not to say that is your cause....
It will spit water all day long on the muffs & not overheat due to tap pressure & the fact that the engine is not under load, (ie not really working)....
Water in all eight cylinders?.....
Did it diesel when you shut down.....
Refresh my memory, how old are the risers/mans?........
Is this standard cooling or closed?......​

 

[wvit1001]

Re: Stuck on lake today! overheated and locked up!

Your welcome. Now that it has blown up and there was water in the cylinders the only thing to do is pull the heads and see what happened.

 

[wvit1001]

Re: Stuck on lake today! overheated and locked up!

I don't think blowing a gasket would put water in all the cylinders though. It could have ingested water through the manifolds but you wouldn't think it would get in all the cylinders that way either.

Maybe you should just clear out the water, change the oil and run it again until something else blows up.

 

[Haut Medoc]

Re: Stuck on lake today! overheated and locked up!

Well just when I got my 1990 Four Winns 225 Sundowner with 5.8L OMC/Cobra running good this happens.

I have had the boat out several times in the last 2 weeks since I got the points issue corrected. One time in about 8 outings the temp gauge spiked up and I shut the engine off for a bit and then everything was fine.

Well today I was out and the temp gauge was at 150-175 for the whole afternoon (1.5 hrs of start and stop). Then I noticed during a 5 min run of WOT the gauge spiked up to 230 F or so. I shut it down to let it cool.

Well I was sitting there watching the engine while it cooled, making gurling noises from the water being so hot. Then all of a sudden it is as if it BELCHED a big bubble, the motor actually moved. I was like oh ****. I had a bad feeling I had water in the cylinders.

I tried to turn over the motor and it wouldn't budge. Yep, water in cylinders. I proceeded to spend the next hour pulling all 8 plugs, turning motor over to clear pistons of water, and then reinstalling plugs. It fired up and I went to dock. Some questions:

1. Why did it overheat? I have removed and inspected impeller in last 3 weeks, everything looked fine and while running it with muffs it sucks water in and spits it out like it should.

2. Should I go ahead and replace thermostat?
I'd pull it & at least look at it.....

3. What was that belch noise and how does water actually get into combustion chambers?
Cracked head, bad riser/man or joint between them....
Blown head gasket......
But if you have water in all 8 I doubt head gasket....

4. Do I have to change the motor oil now that there is probably water in it?
I would.....

5. Does anyone know of an easier way or different tool to use to pull those damn plugs? I use a spark plug socket and a 19mm open end wrench as you can't get a socket wrench on it due to angle.
A universal & a thin walled socket....

Frustrating weekend as my well went out yesterday too! Hell I am afraid to get off the couch now!

Thanks,

Jeff

Hope it gets better.....
You need to devise a way to pressure test your engine's cooling system....

 

[fireicyhott]

Re: Stuck on lake today! overheated and locked up!

Thanks Haut,

I will check it out this week and weekend. I will pull it out of water and check/change impeller, thermostat, check risers, circulating pump, etc.

Risers are original as far as I know, 300hrs and 1990 model.

As far as I could tell there was water in all cylinders.

Thanks for the help.

 

[gdombroski]

Re: Stuck on lake today! overheated and locked up!

This is the only type of plug wrench that works on my 5.8.
http://www.partsamerica.com/ProductDetail.aspx?MfrCode=ALT&MfrPartNumber=010326&CategoryCode=3411S
Any auto parts store has them

 

[fireicyhott]

Re: Stuck on lake today! overheated and locked up!

Thanks gdombrowski I will pick one up before the weekend. That should help.

Can I use a 160 deg auto thermostat on my 5.8L? or is a marine thermostat any different?

Jeff

 

[Dante04SRT]

Re: Stuck on lake today! overheated and locked up!

I just glanced through the posts so don't attack me if its already been stated...

First, forget about "repairing" the problem with a thermostat or anything else to try to "fix" the problem just yet.......

First, I'd do a compression test... If you're unfamiliar, its VERY easy and VERY inexpensive.

$20 will get you the tester at most auto parts places, and 30 minutes of VERY basic wrenching will give you results you can actually use. I should have followed this advice FIRST when it was given to me, but I waited and wound up having to buy a complete engine!

Second, if the compression test comes back with a low cylinder, its unfortunate, but you are going to have to remove the head(s). Its a fact, simple as that. (edit) If compression is low, you might do a leakdown test too before head removal, but with the other symptoms, it sounds like there is something internally wrong.

If the compression test comes back good, all cylinders within acceptable #s, THEN go ahead and buy a thermostat and DEFINITELY change that impeller; They're pretty cheap (at least on Mercs) and its good insurance.

If everything checks out ok, pull the manifolds/risers. $38 is what they charged me to pressure test mine. Besides that, when you pull 'em, its a good excuse to change the gaskets.

I'm no pro, but all of the same info was offered to me a few months back when I was in similar shoes...

See: http://s201.photobucket.com/albums/aa211/dante04srt/boat/problems/

[edit #2] I was thinking about the "water in all cylinders" and wondered, are the 5.8's intake manifolds water cooled as well? I can't imagine them not being, but... Still... its wierd how all 8 would have been full of water. ????