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5.7 mercruiser with water in cylinders

jbeikmann

New member
I am new to boats! Pretty much know nothing about them. Good idea to buy one right?!?!
I went to start my boat last week for the first time of the season. After winterizing it, I reconnected all my hoses, put my muffs on and started it up.
After it ran for a few minutes i turned the boat off, all seemed good.
Decided i would like to check charging voltage just to be safe. Turned my muffs on, and it took me about 2 minutes to actually get in the boat and start it.
Once i turned the key, the engine would not crank. Like it was locked up.
I turned the water off, engine started fine, ran good, turned the water back on and once again all seemed good.
But now i went to start it again and it seemed the engine is full of water, even getting into the oil.
I pulled the plugs on it and it seems to have water in a few of the cylinders, Ones with open exhaust ports is my guess?
My main question is what would cause water to get into the engine just being on muffs??
Haven't even had it in the water yet.

Thanks for anyone willing to help!!
Jason
 
Pulled all the plugs on the block, dug out the plugs with a pick because they seemed to have some gunk in the drain holes of the plugs. Pulled the plugs off of the exhaust manifolds, pulled hoses, and poured antifreeze in the block until pink fluid came out of the plugs. Thanks for the reply by the way!
 
You bought it from a private seller.-----Did previous owner winterize it properly ?------Best look it over carefully an inspect for cracked heads / manifold and block.
 
Bought it privately. Previous owner had new Jasper engine installed the previous year to me buying the boat. Have all the paperwork for it. So I'm assuming I must not have done something quite right winterizing it.
I have inspected the exterior of the block and it all seems good. Like i mentioned earlier, it is weird that it would run fine with no water hooked up. I had only ran it for maybe 30 seconds before turning on the muffs.
 
Would that have anything to do with getting water in the cylinders though?
I had also just previously ran the boat with the muffs on, so it wasn't completely dry...
 
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There are two ways to winterize. Method one, which I prefer, is to drain all the water out of everything until it is "dry" inside. Since there's nothing to freeze, there's zero risk of damage. Method two is to flush every crevice with a heavy solution of antifreeze and water mix. This also is supposed to prevent damage due to the extra low freeze point of the heavy solution. The disadvantage to this method is the chance that your solution is too weak for the conditions and it freezes anyway.
Whenever you buy a boat you should have it professionally looked over by a marine surveyor or at least a mechanic. The seller should pay for this and provide you with the report. If you don't then you must be open to the possibility that it could be full of major problems.
I hope it isn't anything like that and that it is just something simple.
 
o2batsea, I dumped straight antifreeze into everything. My thought was that if there was any water somewhere, the antifreeze would still be strong enough.??
 
The Mercruiser owner's manual is pretty specific about how you do this. Do you have it? If not you can get one online in .pdf format. They tell you to use the engine's circulating pump to flush the antifreeze throughout the block until it comes out the exhaust. If you don't do it like that there's a chance that the antifreeze won't get everywhere.
 
Ayuh,..... So now drain, 'n isolate the block's coolin' passages, 'n pressurize to 'bout 15 psi,........... 'n Listen,.....
Then follow the sound to the problem,....
 
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