Yanmar 2GM - water in oil - help!

[Cheechako]

Originally Posted by dr_c

Since it will be a couple of weeks until I get to putting everything back together (head's at the shop, parts haven't been ordered, we're getting more snow), I went up this evening to spray both cylinders with WD40, put one at TDC and shove a rag in the other one. The ridge was just carbon and dissolved in the WD40 - no ridge that I can feel. (knocks wood) Starting to think I'll feel pretty good about this little motor once it's back together. (keeps knocking wood)

[dr_c]

Originally Posted by Chas Erwin

Agreed that water in the combustion chamber can lead to gasket fail - no matter how it got there and provided it was present there for a spell. But even with these additional facts - one would still be interested in opportunity to examine mixing elbow to assist the diagnoses. But - if it is in the landfill then no problem.

Charles.

Was on the boat this afternoon and finally worked the mixing elbow off of the exhaust hose (which will probably need replacement now that I've wrestled with it. yuck. getting to the water muffler will be a PITA). Anyway, the mixing elbow looks perfect - just the barest evidence of corrosion on the very edge of the internal baffle, where the water and exhaust mix. Must have been a radical event to get water up into the mixing elbow and into an open exhaust valve. . . assuming that's what happened.

Machine shop will look at the head next week . . . i hope. . . .

[DeepFrz]

Don't throw your mixing elbow away, it sounds good from the way you describe it. If you can post a few pictures of it.

Edit: by the way, the water in oil the second time around could have been caused by residual mixture left in the crankcase. Unless you have a pan drain you will not get all the oil out. Even if you did there would still be some water left in the oil galleries, etc. It usually takes 2 or three changes and filter changes to get all traces of water out of the oil.

So the next question is, what is the oil pressure, really?

[Nor'Sea 27]

So to sum up:
Water did not back feed to the cylinder head via a failed elbow chamber separation and so hydro-lock (if any) did not come from this source. (Also means you don't have to get a new elbow yet by the way)
You said you did not cause hydro-lock by cranking the starter motor endlessly until motor stopped abruptly.
There is sign of water in a cylinder according to your photos.
Pretty much leaves a head gasket failure or head structural failure. The shop will tell you once they look over the gasket and conclude the testing.
Keep us posted.

Charles

[maine50]

A antisiphon device clog or failure is commom cause of water in oil. Tim-

[Nor'Sea 27]

Tim It is possible - true enough.

However, it would be difficult to siphon water through the flexible vane sea water pump which is at rest. Moreover, there is no evidence of water in either cylinder and apparently there was no evidence of corrosion in the head exhaust runner(s) either.

Absent evidence of water flowing (back) into a cumbustion chamber/cylinder it is difficult to see how water could reach the crankcase via siphoning of seawater.

Charles

[dr_c]

No real updates on the cylinder head rebuild and reassembly - the local yacht service company in Portland has a great Yanmar mechanic, but he's too busy working the local flower show and boat show to get me the paperwork I need to sign before he'll send the head to a separate machine shop for crack testing, valve job, etc. This is despite multiple calls and an email just trying to get the paperwork. Maine is a weird place. Folks just don't want to work. Wish I had the option.

The down-time on the project has given me time to snap a couple of photos of my mixing elbow for interest's sake -- as I've said, it looks perfect to me, but I'll probably be replacing it, since I don't want to discover it has a thin spot that wears through in a few dozen more hours. It's off now, so cheap insurance.

Separately, the down-time has given me time to pull the nasty-looking heat exchanger on the Yanmar. If anyone knows of a good shop in New England or on the East Coast that I could ship the exchanger to for testing, cleaning and painting, please let me know - I'll be posting a separate thread soliciting advice.

Thanks, all. I'll post more as this comes along (and starts trodding towards completion).

-T

[DeepFrz]

Call Maine Sail, Compass Marine, he is somewhere in Maine. I don't know how busy he is but I'm sure he could help you. Check out his "How To s". There is one there on cleaning up a heat exchanger.

Compass Marine "How To" Articles Photo Gallery by Compass Marine at pbase.com

[Nor'Sea 27]

Maine is no way weirder than Portland Oregon - but I digress.

Your Yanmar expert is not sufficiently motivated. Suggest you obtain name of machine shop from Maine Sail (Compass Marine) re- obtain your head and personally deliver same to the guy who is actually going to perform the testing and rehabilitation. I do not see anything of value your Yanmar guy offers in addition to what the machine shop will provide if you dealt direct.

Guarantee you will get better service, questions will be answered, if you deal direct. Moreover your Yanmar expert will be unable to charge you machine shop price plus 10% for doing nothing much at all.

Charles

[perchance]

As regards your heat exchanger, any decent radiator shop should be able to service it. It is certainly worth a try.

[bombardero]

that happens when the gasket is burned by some who suffered overheating the engine or if the engine was repaired the stock has to be tabrajada to correct any imperfecion gasket that can burn my advice is that if you can not change the oil immediately repaired with if not regularly because it can damage the crankshaft

[Dulcesuenos]

Originally Posted by perchance

As regards your heat exchanger, any decent radiator shop should be able to service it. It is certainly worth a try.

Agree our local radiator shops do almost as much marine as they do authors motive. Btw that pic shows a lot of corrosion looks awful. Not sure its salvageable.

[perchance]

Originally Posted by Dulcesuenos

Agree our local radiator shops do almost as much marine as they do authors motive. Btw that pic shows a lot of corrosion looks awful. Not sure its salvageable.

That lovely green patina makes it more valuable.I wouldn't worry too much about it as it will probably clean up nicely.

[alibaba.e]

Originally Posted by dr_c

Thank-you very much for all of the replies. I needed the sanity check.

As you both speculated, oil pressure was fine for a few minutes before dropping enough to trigger the idiot lamp. I haven’t noticed any oil-in-coolant, just evidence of coolant-in-oil, so am hoping that the low oil pressure is caused by the water or foaming. . . is this realistic?

I really like the idea of filling the water jacket with coolant and seeing if the level drops; although, after sitting for a few months, the coolant level did not drop enough to notice (remove cap, stick in finger, yup – coolant, recap). Assuming the block passes this check, I plan on:
1) Taking the head to a machine shop to be checked for cracks and ‘level.’
2) Replacing the oil bypass valve. Easy enough to do and a ‘suspect.’
3) Replacing the exhaust mixing elbow (looks OK, but I understand this is a good idea, since it’s apart)
4) Reassembling

I’m tempted to leave the oil pump alone since, after changing the oil and (briefly) running the engine, the oil pressure light didn’t come on right away. Not to mention that having the head off doesn’t seem to improve the accessibility of the oil pump. Anyone have experience replacing the oil pump on this motor?

Thanks – and please cross your fingers for me that a ‘spun bearing’ is NOT involved. . . .

-Tony

PS - Gord, thanks for the welcome. When I was thinking about where to ask this question, I googled 'yanmar' and 'Gord' to come up with the appropriate forum. . .

Water coming in through heat exchanger on oil system

[dr_c]

Picked up the heat exchanger from the radiator shop, this morning after being out-of-town. They knew exactly what to do and $72 later, it's back - painted, pressure-tested to 25 PSI and with a corroded but-not-yet-leaking hose fitting repaired. Thanks, Portland Auto Radiator!

Still waiting on the head from the machine shop. I'm sure they were displeased by my instruction when authorizing the work: "Disassemble, inspect, check for flatness and cracks and then call me before proceeding." If the valves look good, I may not have any work done; why grind the valves unless they need it?