Doug, What you hear is most likely a vacuum break. Yes, it is supposed to stop water from syphoning into the engine. However, another way for water to naturally flood in after shutdown is by having the stern wave catch up to the transom and rush into the exhaust hose. The vacuum break doesn't prevent that.
You could buy or borrow a coolant system pressure checker. They attach in place of the radiator cap and you pump it up by hand. Usually about 15 psi. You can observed how quickly the pressure bleeds off to help determined the location severity. Josh Oct 27, 2023 09:04:31 Doug Mountjoy via CnC-List <cnc-list@cnc-list.com>: > Thanks Josh, > This Yanmar 4jhe doesn't have a shutdown cable or decompress lever. It does > have a bleed for the exhaust on shutdown you can hear gurgling Ina cockpit > drain. This should prevent water backing up into the engine. > I'm now hoping that the saltwater won't severely damage the engine. > > Douglas Mountjoy > 1988 C&C LF 39 > Mexico at large > 1984 Sabre 34 > Port Orchard, WA > > > On Thu, Oct 26, 2023, 23:38 Josh Muckley via CnC-List <cnc-list@cnc-list.com> > wrote: >> Water doesn't have to necessarily back up the exhaust from outside or from >> condensation. If, when you're laying the boat up, you don't have sufficient >> exhaust pressure to blow out the coolant, it only has to back up the elbow a >> short distance. The easiest way for this to happen is to use the decompress >> lever so as to prevent the engine from starting while running the starter to >> pump winterizing glycol through the engine. Don't do this. The problem is, >> without compression the coolant doesn't get blown out the exhaust. >> Similarly, pulling the engine stop to shutoff fuel does a similar job of not >> creating enough exhaust pressure (cause no combustion). Better than >> decompression but not good enough. If you're running wintering antifreeze >> through the engine, run the engine at a moderate throttle to suck the glycol >> quickly into the engine. When its gone, don't be too quick to stop the >> engine. Let it go long enough to blow the elbow dry, then shut off the >> engine. You can also have someone watching the exhaust to go dry. The >> whole thing is a bit precarious. Left hand on the elbow and right hand on >> the raw water pump cover to check for over heating is good practice if you >> have access. That leaves your right hand close to the fuel shutoff cable >> when it is time. >> >> Of course water in the cylinders (before it leaks through the rings to mix >> with the oil) would likely cause rust and stuck rings when you go to start >> it in the spring. So like the other listers have suggested, I'm leaning >> towards oil cooler leak too. See if you can pressure test it. >> >> >> Good luck, >> >> Josh Muckley >> S/V Sea Hawk >> 1989 C&C 37+ >> Solomons, MD >> >> Oct 26, 2023 20:14:17 Doug Mountjoy via CnC-List <cnc-list@cnc-list.com>: >> >>> Water from the exhaust seems unlikely at this point, it would have to flow >>> uphill quite a ways to get into the exhaust manifold. And plus this engine >>> is a diesel so no carburetor or anything like that. the only possible thing >>> I can think of is either a blown head gasket or the oil cooler. >>> >>> Douglas Mountjoy >>> 1988 LF 39 >>> Mexico at large >>> 1984 Sabre 34 >>> Port Orchard, WA >>> >>> >>> On Thu, Oct 26, 2023, 16:53 Rick Brass via CnC-List <cnc-list@cnc-list.com> >>> wrote: >>>> I'm not sure that condensation would be a likely source for any >>>> significant amount of water to get into the engine oil. The only real >>>> point of entry would be some sort of reverse flow through the EGR valve, >>>> which doesn't seem like it would be likely to admit much water vapor - >>>> particularly in a semi-arid area. And any rainwater would need to get in >>>> through the carburetor and likely collect in the intake manifold and have >>>> little chance of leaking into the oil pan. >>>> >>>> >>>> The suggestion of a leak in the engine oil cooler seems a likely >>>> possibility, assuming you have one on that engine model. >>>> >>>> >>>> Another might be having water in the exhaust manifold when the engine was >>>> shut down that leaked back into the engine through partially opened >>>> exhaust valves. I lost an engine on my 38 that way: The PO had cut corners >>>> when the original A4 was replaced by the diesel, and when the boat heeled >>>> to port while sailing water in the lines and muffler could get back into >>>> the exhaust manifold. Was OK for a long time because starting the engine >>>> blew the water out. But I lost a rudder, had to be towed in, and during >>>> the months that the boat was on the hard during the replacement the water >>>> leaked into the engine and corroded piston rings to the cylinder wall so >>>> the engine would not start - which required a rebuild or a new bobtail >>>> engine (which turned out to be less costly). Never looked at the oil pan >>>> on the old engine, but seems pretty likely there was water in there. >>>> >>>> >>>> Of course, YMMV. Good luck with the engine. >>>> >>>> >>>> Rick Brass >>>> Washington, NC >>>> >>>> -----Original Message----- >>>> From: Stus-List <cnc-list@cnc-list.com> >>>> Sent: Oct 26, 2023 7:06 PM >>>> To: Stus-List <cnc-list@cnc-list.com> >>>> Cc: Korbey Hunt <kampf2...@hotmail.com> >>>> Subject: Stus-List Re: Water in the oil >>>> >>>> >>>> >>>> Yes. Good possibility, my boat is in Loreto/ Puerto Escondido. I was in >>>> San Carlos a few years ago. Fun town. >>>> >>>> Get Outlook for Android[https://aka.ms/AAb9ysg] >>>> ---------------------------------------- >>>> *From:* Doug Mountjoy via CnC-List <cnc-list@cnc-list.com> >>>> *Sent:* Thursday, October 26, 2023 12:27:55 PM >>>> *To:* Stus-List <cnc-list@cnc-list.com> >>>> *Cc:* Doug Mountjoy <svrebeccal...@gmail.com> >>>> *Subject:* Stus-List Re: Water in the oil >>>> >>>> There was enough water to turn the oil to chocolate milk. Could be >>>> condensation, there was a couple of nasty storms that came through here >>>> this summer. I'm in San Carlos MX. in the desert. Didn't have this problem >>>> last year. I'm kinda thinking it might be the lube oil cooler. >>>> >>>> Douglas Mountjoy >>>> 1988 LF 39 >>>> Mexico at large >>>> 1984 Sabre 34 >>>> Port Orchard, WA >>>> >>>> >>>> On Thu, Oct 26, 2023, 11:32 Jeff Nelson via CnC-List >>>> <cnc-list@cnc-list.com> wrote: >>>>> How much water? A little could be condensation... >>>>> >>>>> Cheers, >>>>> Jeff Nelson >>>>> Muir Caileag >>>>> C&C 30 - 549 >>>>> Armdale Y.C. >>>>> >>>>> On 2023-10-26 14:59, Doug Mountjoy via CnC-List wrote: >>>>>> I have a Yanmar 4JHE in my boat. After 4 months sitting on the hard, I >>>>>> have water in the oil.Does anyone know where the most likely place for >>>>>> leaking is? >>>>>> When I put her away last spring, I had flushed the engine and let the >>>>>> hoses drain. >>>>>> I'm at a loss here. >>>>>> >>>>>> Douglas Mountjoy >>>>>> 1988 LF 39 >>>>>> Mexico at large >>>>>> 1984 Sabre 34 >>>>>> Port Orchard, WA >>>>>> >>>>>> Please show your appreciation for this list and the Photo Album site and >>>>>> help me pay the associated bills. Make a contribution at: >>>>>> https://www.paypal.me/stumurray >>>>>> Thanks for your help. >>>>>> Stu >>>>> Please show your appreciation for this list and the Photo Album site and >>>>> help me pay the associated bills. Make a contribution at: >>>>> https://www.paypal.me/stumurray >>>>> Thanks for your help. >>>>> Stu >>>> >>>> >>>> >>>> Please show your appreciation for this list and the Photo Album site and >>>> help me pay the associated bills. Make a contribution at: >>>> https://www.paypal.me/stumurray >>>> Thanks for your help. >>>> Stu >> Please show your appreciation for this list and the Photo Album site and >> help me pay the associated bills. Make a contribution at: >> https://www.paypal.me/stumurray >> Thanks for your help. >> Stu
Please show your appreciation for this list and the Photo Album site and help me pay the associated bills. Make a contribution at: https://www.paypal.me/stumurray Thanks for your help. Stu
