I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

Zane L

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Jul 5, 2010
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7
Hey,
So Im new to this but have been tryin to read other fourms to figure out what my problem is. I have a 1998 24' Conquest with a 5.7L merc crusier motor. So I had just got done finishing putting new exhaust manifold gaskets on and a new carb (no water in motor problem prior to this, so I think although last time I took it out it seemed like it got a little warm) anyway I fire it up fine in the driveway runs good.. put the hose on it and starter makes nasty noise occasionally but still starts, then get out on the water turn it off then back on 3 times for just moving around and the fourth time starter just grinded up the fly wheel (its still ok though thank god)
and wouldnt turnover the motor so I got towed in, I pulled out the plugs and there was water in each cylinder with water pouring out of some cleaned it all out drained about 2 quarts of pure water from the oil. Then turned it over by hand no problem (no funny noises) then turned it over with starter still ok. but water keeps coming out of cylinder two (which has 0 compression?). Then I did a compression test on the whole motor and this is what I got -

1.158 psi /// 2. 0 psi /// 3. 150 psi ///4. 160 psi /// 5.160 psi /// 6. 125 psi ///
7.140 psi /// 150 psi

Some please help, could it be the manifolds or risers? head gaskets? It wasnt this bad before did the manifold gaskets and carb?
 

Bt Doctur

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19,344
Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

no water in/ near the manifold to head gaskets, do you mean riser gaskets?a riser gasket leak can /will put water in a cylinder(s)
cracked manifold, cracked head, cracked block
 

Zane L

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Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

Ya I only replaced the exhaust manifold gaskets not the riser gaskets, Is there a way I could test for a cracked block or head? Could it be a headgasket? Im curious though would a cracked block or head cause all 8 cylinders to fill up with water and fill up the crank case with about 2 quarts of water?

Let me know what ya think
Thanks,
Zane
 

John_S

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Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

Heads got to come off to fix. Head may be cracked, valve bent, or head gasket blew. May have started with leaky manifold/riser gaskets. Remove, inspect, and replace the gaskets as a minimum.
 

TilliamWe

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Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

I disagree that the heads have to come off first. The water in the cylinders is most likely the exhaust manifolds or the riser/riser gaskets. That's the first through about the 5th reason that water gets into the cylinders of a marine engine. headgasket id much farther down the list.

However, the ZERO compression screams bad valves, to me. So the heads probably do need to come off eventually. But I am guessing that you have two problems. Exhaust manifolds/riser/gaskets and cylinder head valves. Good luck.
 

John_S

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Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

However, the ZERO compression screams bad valves, to me. So the heads probably do need to come off eventually. But I am guessing that you have two problems. Exhaust manifolds/riser/gaskets and cylinder head valves. Good luck.

Yep, zero compression means the head is coming off (at a minimum). The exhaust manifolds have to come off to get the heads off. You can take time and run whatever other tests you see fit, or just dig in.
 

Zane L

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Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

Hey,
Thanks for the reply from everyone Im really starting to appreciate this forum thing because I know how mechanics work and I talked to one this morning and he just wanted me to replace the engine for $6500 and wouldnt help me but Im a do it yourself kinda guy only problem is I dont know how the boat stuff works but any way heres the update:

Pulled intake manifold off looked ok. Pulled off the risers and the exhaust manifolds had a bunch of water in them, the riser gaskets didnt look cracked or to be leaking but I dont know for sure. Also the exhaust manifolds and risers look to be newer (brand is Sierra) and the jackets look to be in decent shape with not to much rust. As far as no compression in cyl. 2 do you guys think it could be a bent valve from the hydro lock? Iam probably going to pull the head today. Please get back to me and tell me what ya think? but how did all the water get into the crank case could it have forced water through intake manifold gaskets?

heres some pics of the risers and the work
http://s161.photobucket.com/albums/t235/zanelarsenw/Boat problems/
 

TilliamWe

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Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

Ok, your manifold were the main issue. Yes the zero compression could be a bent valve. Or it's rusted up so bad it won't seat.
So you need to determine what is wrong with the manifolds/risers. Cracked internally? Gasket surfaces so not straight that the gaskets don't seal? Etc.
Then that head has to come off to see the valves. And you could stop at that, but even I, the "king of cheap", would remove the other head and have its valve checked.
 

John_S

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Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

Hey,
I have a 1998 24' Conquest with a 5.7L merc crusier motor.

FYI: The picture of the motor indicates a '87 or earlier. Those are the old perimeter style valve covers. No mercuiser labels, would indicate an "unknown" motor. Not sure why they would put an old style motor in a '98, vs just a long block replacement???
 

Zane L

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Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

Hey,
Thanks for the info I didnt get to taking off the valve cover today but I will tomorrow I really appreciate this site, all this puts me a little more at ezze and is a big help.

As for the engine being older, ya the guy that I bought the boat from whom I think screwed me in the begining an failed menchine alot of things, finally said he bought it with a bad motor and replaced it and sold it to me and after talking to people we realized that the motor is way older, he did tell me it was a marine motor after I chewed him out but wouldnt admit to the year. So is it a merc cruiser motor? Or could it be an automotive one? or is there a way to tell? (Oh and yes when I was sanding it down to repaint after replacing the carb, Orange paint came through the black which indicated to me this is a pretty old motor)

Also on a side note considering the amount of water that was in my crankcase are my main bearings going to be ok?

Thanks for the help guys! Let me know what you think
 

Bt Doctur

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Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

Mercruiser never used Chevy Orange as a primer
 

John_S

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Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

Hey,
Thanks for the info I didnt get to taking off the valve cover today but I will tomorrow I really appreciate this site, all this puts me a little more at ezze and is a big help.

As for the engine being older, ya the guy that I bought the boat from whom I think screwed me in the begining an failed menchine alot of things, finally said he bought it with a bad motor and replaced it and sold it to me and after talking to people we realized that the motor is way older, he did tell me it was a marine motor after I chewed him out but wouldnt admit to the year. So is it a merc cruiser motor? Or could it be an automotive one? or is there a way to tell? (Oh and yes when I was sanding it down to repaint after replacing the carb, Orange paint came through the black which indicated to me this is a pretty old motor)

Also on a side note considering the amount of water that was in my crankcase are my main bearings going to be ok?

Thanks for the help guys! Let me know what you think


As mentioned, it means your motor started life as a Chevy car or truck motor. You might want to investigate your state laws and see if you have other recourse. If it had non-marine parts, the seller was putting you and others aboard at risk.

Things that need to be checked on engine:

- Does it have a marine: carb, starter, distributer, water circ pump, cam, fuel pump, fuel line, flame arrester, alternater

- Does it have brass freeze plugs, marine head gaskets (you will see soon)


You might also want to confirm the engine is a 350, and not a 305. You can do that via casting numbers or measure the bore diameter when you take the heads off.


Back on original issue: Given the problem seemed to be there when running on muffs, most likely a cracked manifold, bad seal between manifold/riser and/or riser/elbow. Since this has the unknown motor, put in for a quick sale, would make sure they installed the exhaust shutters and reviewed the instalation manuals to see if the risers are high enough for your boat and waterline (probably are ok though).

Hydrolock can cause allot of damage. Both heads need to be checked for cracks, even if there is an obvious rusted or bent or broken valve. A bent or broken rod is also possible. If it happened only at idle rpms, probably not though.

I think you can see that you are going to be spending a good deal of the boating season working on this. As stated in the beginning, might want to see whatother recourse you have. If you are staying with it, see if the seller has the original engine. If you are going to replace engine, its worth going back to the original vintage, and having all the correct marine parts and bracketry/pulleys.
 

Zane L

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Jul 5, 2010
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7
Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

Hey,
So I tore the head off and the explanation for 0 compression in cyl. 2 was bc the head was cracked. Ya sucks, but better than a new motor. One thing I was wondering is there a difference between marine head or reg. from the auto parts store?

Also the crack doesnt really explain the water in the all cyl. or does it? but do you guys think that could be explained by the manifolds and risers? And how do I test for cracks in those?

Let me know,
Thanks,
Zane
 

TilliamWe

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Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

Also the crack doesnt really explain the water in the all cyl. or does it? but do you guys think that could be explained by the manifolds and risers? And how do I test for cracks in those?

No.
Yes.
You look for rust inside the exhaust passages. Or block off all the holes and fill the water jackets with water, let it sit, and see if any leaks into the exhaust passages. That's one way, I am sure there are others.
 

John_S

Rear Admiral
Joined
Jun 21, 2004
Messages
4,269
Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

Hey,
So I tore the head off and the explanation for 0 compression in cyl. 2 was bc the head was cracked. Ya sucks, but better than a new motor. One thing I was wondering is there a difference between marine head or reg. from the auto parts store?

Have you id'ed the current head? Is it a 76cc chamber? That would be a guess based on vintage, and assuming you have a 350 with flat-top pistons. But, we don't know where your engine came from. In general, a heavy-duty truck head would be fine, but if you are only replacing the one, it should match the other.

Did it has a stainless steel or ss composite, or composite head gasket? If not, than it can rust and leak, and as a minimum the other needsto be replaced.

Also the crack doesnt really explain the water in the all cyl. or does it? but do you guys think that could be explained by the manifolds and risers? And how do I test for cracks in those?

Where was the crack? But most likely not. You would have to seal off and pressure test the manifolds.

Did you check the pistons to see if they are all nice and straight (no bent rods)? Turned it over a few times, make sure there wasn't any bore damage? Whichever piston is closest to crack, make sure it is inspected carefully.

And is it a 4" bore diameter?
 

Zane L

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Joined
Jul 5, 2010
Messages
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Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

Ya I think it was a composite headgasket which would should I get ? Ya Im going to try and take a look at it today. It just started getting really nice out here (90 degrees Seattle) but its almost to hot to work on the boat.

But ya Im going to pull off the other head today or tomorrow hopefully and inspect the pistons.

Heres some more pics of the head and bank 1
http://s161.photobucket.com/albums/t235/zanelarsenw/Boat problems/
 

TilliamWe

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Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

There's definately water in the exhaust passages in those exhaust manifolds. That's where the water in the cylinders came from.
 

Zane L

Cadet
Joined
Jul 5, 2010
Messages
7
Re: I Need help!!! Hydro locked and water in the oil and 0 compression in cyl. 2

Hey,
So I pulled the other head off and it was cracked also through a water jacket. Now I might be a little worried with having two cracked heads that the block could be cracked because would the cracked heads be able to explain all the water in the oil? Is there a way to make sure the block is ok?

Thanks,
Zane
 
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