Water in #1 cylinder, compression Results what is the verdict?

[compman723]

4.3L GL PWTR Vortec

It has been running bad all spring and I have been thinking it was an electrical problem so i switched about everything then it finally stalled on me and so I pulled the plugs and to my surprise water came out of #1 cylinder. I did compression and they were as follows looking at the engine from inside the boat

back of boat side

150 210
175 165
180 173

towards front of boat


From these numbers it seams to be holding compression and I also have no water in the oil so is it the intake or exhaust manifold cracked? What are good numbers for this? I seam to remember 160 was minimum but I am not sure.

I talked to a mechanic about these engines and he said sometimes when wintering they forget to take out the plug in front of the engine and pour antifreeze in there and tip it up which causes trouble during winter. I just bought the boat this spring so I am unsure of the previous state.

Thanks for all the help!!! and everyone who has helped me so far!!!

 

[Don S]

Re: Water in #1 cylinder, compression Results what is the verdict?

That high 210 cylinder is the one with the water in it, it will be high. The 150 is just barely out and your 180 may also be water.
If I was you, I would take the impeller out of the raw water pump and drain the exhaust manifolds of water. DO NOT hook up water to it with muffs, start the engine and let it run for 15 to 20 seconds. Shut it off for about 5 to 10 minutes to let the rubber exhaust hoses cool, start it again for 15 to 20 seconds.
That should get the water out of the cylinders.
NOW, do another compression test and compare numbers.

 

[Don S]

Re: Water in #1 cylinder, compression Results what is the verdict?

The chances are high, that your water is coming from the riser/manifold gasket leaking.
After you get your compression squiared away, drain the cooling system completely. Then plug off the hoses going from the thermostat housing to the exhaust manifolds. Then remove the raw water pump hose that goes from the raw water pump to the thermostat housing. Adapt a hose to the stat housing so you can pressurize the cooling system with air. It should hold 15 psi.
Do you boat in salt water or fresh water? Ever had any overheats?

 

[compman723]

Re: Water in #1 cylinder, compression Results what is the verdict?

Don, I hope you can still help me out. I decided to get going on this I have been to busy to get working on it since last time I posted. I ended up winterizing it and gettting all the water out.

I did what you said, took the raw water impeller off and ran, sit 20 and ran again and came up with these numbers.

Front of boat

180 180
140 180
180 180

Back of boat

It seams that the 140 could be low but I read in the book that if it is within 25% of the highest # it should be fine. (180*.75 = 135)

The boat runs great without the water problem. When I fired it up it idled perfectly even after sitting all winter so it makes me really confused.

I also did the pressure test and it seamed to hold air. Do is make a difference if all water is out of the cooling system? I drained it but am not sure how to make sure it is really clear of all water.

When you say "riser/manifold gasket" which gasket are you exactly talking about?

Since all this holds could it be a gasket on the exhaust manifold side where the water is getting in when the valves open? Is there a way to pressure test the exhaust manifold?

Sorry for the long delay and I hope you are still around to help out...

Thanks again and much appreciated.

 

[Bondo]

Re: Water in #1 cylinder, compression Results what is the verdict?

When you say "riser/manifold gasket" which gasket are you exactly talking about?

Ayuh,... It's usually the 1 between the Manifold,+ the Riser.....
Or,... The actual gasket Surfaces Of the manifold or the riser....

 

[compman723]

Re: Water in #1 cylinder, compression Results what is the verdict?

Thats what I was thinking, dumb me. Is there anyway to know that would be it? Anyother tests someone could recomend? Do you think the compression test reults are something to worry about?

Thanks again everyone for your help!!!

 

[Bt Doctur]

Re: Water in #1 cylinder, compression Results what is the verdict?

Pull the risers and look inside. Anything other than black sooty walls may mean moisture
Red rust colored ,grey/white ugly looking deposits all indicate moisture.

 

[compman723]

Re: Water in #1 cylinder, compression Results what is the verdict?

I am going to change out the risers manifold gasket this weekend. Sorry for the unintelligent response before I wasn't picturing everything right in my head. After talking to a few more people it seams only possible that the head gasket could be bad because it hyrdolocked while i was cruising. It seams that if the riser manifold gasket was bad this would only happen if i shut it off and turned it back on.

Please anyone point me in the other direction because i would definately rather change the riser/manifold gasket but from what i am thinking and also that the one cylinder is 140 or so while all others are 175+.

Starting over at square 1... These the only two things that could be wrong right? Either head gasket or riser/manifold gasket?

Thanks again!!!!!!

All help is appreciated....

 

[HT32BSX115]

Re: Water in #1 cylinder, compression Results what is the verdict?

it hyrdolocked while i was cruising.

What do you mean by that, exactly?

Were you cruising at 3500 RPM for example, and it hydrolocked at that RPM etc? Did you have a sudden engine stoppage?

That will frequently bend a connecting rod!!

If that didn't happen, then you probably didn't have a hydrolock event "while cruising"

If you were "cruising" and you shut it down, THEN you had a hydrolock event, during a subsequent start attempt, it is most likely a riser gasket, exhaust manifold or riser leak.


Cheers,


Rick