Salt water in cylinders

[Windy sparrow]

After sailing and motor sailing from Abacos to Beaufort NC and setting at anchor for 3 days, when I tried to start the engine it would not turnover. Discovered it was due to cylinders having salt water in them. Yanmar 4JH3E 56hp. It was/is my understanding that this can only occur as a result of turning over the engine too much without it starting (such as bleeding the injectors etc.) or anti-siphon valve being clogged and water syphoning back into the cylinders. I never cranked the engine at all while anchored and saltwater went into the cylinders while anchored for three days. Replaced the anti-siphon valve with new one. Removed the injectors and blew/Emptied water from cylinders, filled and refilled cylinders with oil and then blew it out. Changed the oil and filter 3 times to get rid of any water. Replaced the injectors and it started right up. Motored a couple of hours to boatyard. No problems. Started again the next day to go into travel lift well, no problem. After a week on the hard, went back in the water and engine started and ran fine. Started again departing from Beaufort and sailed and motor sailed to Newport RI. Had water leak at hose going into heat exchanger but not too serious so continued on for last 12 hours. Arrived in Newport yesterday morning. Replaced the saltwater hose and went to start the engine only to discover that the engine wouldn’t turnover. Took out an injector and discovered salt water in the cylinders again. What can be causing this????

[cr180]

Oil cooler leak?

[nuku34]

Could be a blown head gasket.

[jamhass]

Originally Posted by nuku34

Could be a blown head gasket.

Not likely if salt and a fresh-water cooled engine.

If an oil cooler leak, salt would be in the crankcase, less likely in the cylinders.

Since you replaced the anti-syphon valve, I guess more likely from the exhaust, so check carefully for syphon potential (good loop in the exhaust hose, etc.

Another check: do you normally close your engine raw rater inlet when leaving the boat? If not, then recheck the entire a-syphon plumbing.

For what its worth, I long ago eliminated my a-syphon valve and plumbed a direct overboard "piddle" (about 1/8-inch orifice.) When I start the engine, I look immediately for the piddle, Too little flow and the impeller is bad or I forgot to open the seacock. Too much flow and there might be an obstruction in the raw water circuit.

[mvweebles]

Any change in trim or load that might put the anti siphon below waterline? Maybe your exhaust elbow is toast and no longer separates water?

Your manifold is below waterline. Somehow water is backing up through the exhaust elbow.

[jkishel]

Are you sure it is salt water and not coolant in the cylinders? I have seen several JHE’s with corroded exhaust manifolds allowing coolant into the cylinders. These were small leaks that accumulated over time, as you describe. To confirm or rule this out, pressure test the system. Be patient, make sure the system holds pressure for a few hours as the leak can be small or blocked with crud. The only fix is to replace the manifold.

[SY Harmony]

Do you have a mushroom thru hull or a “speed grate” style?
A “speed grate” can cause positive pressure in the raw system and push past the impeller blades. Filling the exhaust until the engine is back filled.

Speed grate / scoop style
https://www.amazon.com/GROCO-Bronze-...53944904&psc=1

[mvweebles]

On second thought, how old is your exhaust elbow?

[SailingHarmonie]

Let's back up a bit, and get more data to help sort stuff out.

Is this a new installation? If not, has ANYTHING changed in the exhaust or raw water plumbing?

Is the boat new to you?

Did you motor right before dropping anchor?

If you ran the motor when anchoring, and three days later the engine has seawater in the cylinders without running or moving, odds are VERY good that you are syphoning. I would struggle to come up with ANYTHING else that is likely.

We can not even begin to come up with anything other than wild guesses as to why this would happen without seeing detailed pictures or drawings showing the exact layout of the system with elevations, hose sizes, water lock capacities, etc.

Wet exhaust system design is quite fussy, as you can see by the number of people posting on here who have exactly this kind of problem. I have seen many "professional" engine installations that were hopelessly bad, and that includes installations by boatbuilders.

[Windy sparrow]

Discovered elbow exhaust leak. Always seems so simple once you know what it is….. thank you to all who commented and offered their insight.

[mvweebles]

Originally Posted by Windy sparrow

Discovered elbow exhaust leak. Always seems so simple once you know what it is….. thank you to all who commented and offered their insight.

Thanks for update. For future reference, was this an older elbow and leak was internal rusted-out area? Or some sort of other defect?

[Windy sparrow]

Old rusted, corroded. Thanks, windy sparrow

[MicHughV]

Had this happen to me....many miles from any repair facility.
I had to remove the cylinder head to siphon all the salt water out.
Then bang on a piston with a large hammer on a piece of wood I had laid on top of the piston, till it reached bottom.
Then put everything back together using all the original gaskets, etc.
Against all odds, it started right up.
Then followed several oil changes.
I couldn't fix the exhaust elbow, but patched it up.
Thereafter I would close the seacock immediately after the engine was shut off, and re-open it, right before cranking it up.
Engine smoked a little, but otherwise ran fine, until I could affect a more permanent repair.