Water in engine

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R

Russ

I have a Hunter 420 Passage, 2004 model, with a 56 hp Yanmar. When I cranked it 2 days ago, the engine turned out to have at least 5 gallons of salt water in the crankcase and head. Needless to say I am headed to an expensive repair. The problem is we cannot figure out what happened. Everything was fine when we docked it the weekend before after motoring 5 hours in calm waters. When I cranked it, it turned over slower that usual as if the battery were weak. It caught on about the third revolution and idled a little rough, which is usual. After no more that 5 seconds, I shifted in reverse and it went "clunk" and quit. I ascertained that there was nothing wrapped around the prop and checked the battery voltage. All was well, until I checked the oil, which clearly had water in it. We have ruled these things out: 1. Overcranking. It did not turn over more than 3 or 4 times, and then it cranked, which would have forced the water out of the aqua lift anyway. 2. Clogged anti-siphon valve. Air passes through it. 3. Heat exchanger. Proper level of coolant in the plastic tank, and it does not have any emulsified oil/water in it. So, why did it flood? Thanks, Russ Simpson
 

Rick D

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Jun 14, 2008
7,204
Hunter Legend 40.5 Shoreline Marina Long Beach CA
Couple of Thoughts

...that seem to be reaching given your explaination. First: was the boat loaded heavily at the stern with a large number of people for the motoring or at the deck after? Even that shouldn't have caused it, but I have heard of cases where it was a cause. Did you have large swells at anchor or on a mooring? Again, unusual but I have seen cases where boats rolling in large or steep swells with their engines off had a 'water hammer' effect that caused water to rise up through the loop and fill the muffler causing water to enter the exhaust. What I find interesting in your case is that the water was in the crankcase and the engine ran. In those other cases I mentioned, the engine would not have turned over since the cylinders would have been filled with water. So, in retrospect, those senarios would not apply and I would have to think it must have something to do with the raw-water routing. I hope you turned this in to your insurance company. If not, you should. Good luck, I hope someone else has a better notion of what to consider. Rick D.
 
A

Allorshas

water in crank ase

Had similar problem last year and luckily ended without much expense 1) 5 gal of water is really a lot !!! So too much compression and engine will not turn easily Its not related to battery .if you force it it could result in severe damage First empty the oil and water in crank case and refill with regular oil 2) decompress engine , close water intake, and try to make it turn a few times If it turns easily without making weird sounds then you might be lucky 3)If so recompress and start Run 5 minutes at lowest rpm with water intake still closed 4) if it started corectly change oil again It is very long process to get rid of all the water in crank case you might need to change oil 4/5 times before it stays brown in my Yanmar water came from a leaking water pump It was the gaskets and bearing inside the pump Very difficilt to see from outside A friend of mine had water in is engine coming from water entering is exhaust when sailing back wind with 2 ft wakes
 

RichH

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Feb 14, 2005
4,773
Tayana 37 cutter; I20/M20 SCOWS Worton Creek, MD
Water pump !!!!!

Remove/dismantle the raw water pump and see if one of the seals has 'gone'. You may want to do a 'pressure decay' test on the pump - On a bench apply ~20-30 psi water pressure to one side of the pump, block the opposide side, close off the inlet valve and water for the pressure to go to zero ... or see water coming through the seal on the 'crankcase' side. On most Yanmars (any many other engines) the raw water pump is direct coupled to gearing inside the crankcase; if the seal between the water side and crankcase side fails you can easily fill the crankcase. Best thing to do is quickly drain the crankcase and immediately over-fill with 'Marvel Mystery Oil" (automotive speed shop stuff --- if MMO not availaable then ATF can be used), turn the engine by HAND ONLY - use a socket wrench on the crankshaft nut - to be sure that the piston rings are not stuck to the cylinder walls (If stuck then STOP dont force it or you will break the rings *** see below), if rings are free - then spin the engine carefully on starter ONLY (DONT LET IT START), let sit for a few hours/days, then start the engine and let run at idle & AT NO LOAD until warm, change the oil to regular, restart and increasing the load very s-l-o-w-ly, change the oil again (and again). This should 'repolish' the engine internals and remove of most of the 'rust blooms' on the cylinder walls, piston ring grooves, etc. You may need to repeat the whole process after a month or so of 'run time'. Once the engine is 'running' keep changing the oil after running if the oil has any 'hint' of a milky color or brown-milky color. *** if the piston rings are stuck, you can sometimes break them free by dumping the MMO down the injector holes, let it soak and then *gently* try rocking the crankshaft back and forth BY HAND with a long arm wrench (do NOT force), keep rocking back and forth without forcing, occasiionally dump a little MMO down the holes and 'eventually' the rings will (usually) break free. Note when attempting to restart the engine BE SURE to have a rag etc. ready to jam into the air intake just in case the engine starts to 'run-away'. Alway keep a large rag handy to jam into the air intake (not the inlet filter/silencer .... the actual intake) in case the engine 'runs away' (tries to gain infinite rpm). hope this helps.
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
Cracked head

Since the likelyhood of raw water getting into the engine through the cylinders AND the engine even cranking is almost 0, I'd bet that the engine has a cracked head which is allowing the raw water pump to dump salt water into some part of the head or block. The engine would run fine initally until the salt water filled up the crankcase. It would then most likely stall from all the fluid getting wipped around by the crankshaft. It sounds like you got the problem identified quickly enough to prevent serious damage to the cylinder walls and bearings but you will definatly want to pressure test the raw water system. You could take the raw water outlet hose off the heat exchanger and plug it and then Rub Goldberg a pump to apply pressure and then watch to see if the pressure falls off after you stop pumping. My first take on the Goldberg pump would be to apply lung pressure to the inlet hose after the raw water pump by mouth. If your inlet hose is like mine this could be a Kodac moment so make sure you are alone. You might get unlucky and be able to use a funnel on the inlet hose. Just fill it with water and see if it drains out. It would have to be a pretty big crack for this to work though.
 
Dec 2, 2003
4,245
- - Seabeck WA
Well Bill,

The only problem with that idea is that the engine is only 2 years old. That means it's fresh water cooled. There's no saltwater near the engine except for the exchanger. Hmmmm, RichH was talking about a failed raw water pump seal. I've not seen a Yanmar raw water pump that was anything but belt driven. First thing to do is call Yanmar. This is nuts.
 

Rick D

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Jun 14, 2008
7,204
Hunter Legend 40.5 Shoreline Marina Long Beach CA
I'm With Fred

I think Rich H. may have nailed it. If your raw water pump is gear-driven (I think it is, mine on my 4jh is...) it could be from that. However, you have warranty and insurance issues to deal with, so protect yourself by putting both Yanmar and your insurer on notice. Even if the warranty is gone, this is one of those deals where Yanmar may step up to the plate to handle it. I assume you have already flushed the engine a couple of times. Also, photo everything and it's a good idea to have someone with you when you pull the pump to attest it is the same one later (assuming you do it yourself). My gut feel is that the internals are OK, but you want to take care to protect yourself. Let us know what you find out. Rick D
 
B

Benny

It's going to be a hard swallow for

the insurance company. Sounds to me like a compound failure. Most likely a craked head or failed head gasket caused by or coupled with a heat exchanger failure. Checking the remote coolant tank may not reveal an exchanger failure. Did the engine overheat? An engine top dissasembly will have to be conducted and they will be able to tell what the problem was. Yes, raw water pumps are belt driven with the exeception of the one cylinder 1GM. Good luck and let us know the outcome.
 
Jun 8, 2004
3,009
Catalina 320 Dana Point
Russ, That is something unknown here as you

state water level in plastic overflow tank was okay, but how was the coolant in the engine ? Did you check to make sure water jacket on engine was also full, and was it contaminated with oil? if there's a break in the line or at the pressure cap the vacuum won't pull coolant back into the engine when it cools. If there's no coolant in the jacket the temp gauge may not work, you wouldn't know you were overheating, heads warp etc. etc.
 
C

Clyde

Possible Oil Cooler Failure? *o

Since we're speculating, I would suspect that you had an oil cooler failure. The seawater intake circulates seawater to the freshwater heat exchanger and a separate oil cooler (if you have one) before dumping the heated seawater to the mixing elbow for discharge overboard. For seawater to enter into the engine from the closed freshwater cooling system, you would have to have two failures; a failure in the freshwater heat exchanger letting seawater enter into the closed freshwater loop and a second failure in the engine gaskets. The oil cooler is usually inline between the seawater intake and the seawater intake pump. A single failure of the oil cooler would cause a lot of seawater to enter into the engine crankcase. If you had a mixing elbow failure, it's possible that seawater corroded through the elbow and corroded the metal on your cylinder head allowing seawater to enter into the cylinder and eventually into your crankcase. Since it appeared to happen almost overnight, the most likely cause could be an oil cooler failure. Fair Winds, Clyde
 
Nov 1, 2006
2
- - Whisper
Thanks fur the suggestions.

Thanks for all your input. We will check out the water pump and impeller. Another long shot is that the 1.5 - 2 knot current was strong enough on an unusually high tide to force the raw water up and in. Like I said, it's a long shot. Also, we are checking the emulsified liquid to make sure it is saltwater, not freshwater. It is possible, though not likely, that vandals (we have some) shoved my dock hose up into the exhaust pipe (which they could reach from the dock) and flooded it. Have put ins co on notice. Vandalism would be covered; equipment failure not sure. We are in contact with Yanmar engineers to see if there have been other probs. Also, have submitted an email to Hunter tech support. No answer yet. Russ
 

Rick D

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Jun 14, 2008
7,204
Hunter Legend 40.5 Shoreline Marina Long Beach CA
Insurance Side Note, Russ

Altho it is a bit murky, mechanical failure exclusions on insurance policies are usually construed to exclude the mechanical item that failed but cover the damage that resulted from it. Examples might include, not covering the spreader that failed but covering the mast and any other damage, excluding the braker, but covering the rest of the panel and wiring, etc. This may go so far as to include failure of your salt water pump or oil cooler and paying for the rest (subject to your deductible). So, don't just make any assumptions about coverage. Good luck, RD
 
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