Not sure if this is common on Yanmars, but on VW diesels, a common source of slow coolant leaks is the head gasket. There are a few places where coolant passages can seep coolant into the combustion chamber, which occurs during cooldown when the engine is stopped. During operation, the higher pressures of both the oil passages and combustion chamber don't allow coolant to escape, and in the worst cases, cause the coolant system to the overpressurized due to combustion gases. A symptom of the latter is to install a pressure gauge on the coolant tank, and run the engine from cold. If pressure builds up quickly, then you have combustion gases entering the system, as pressure from heat will take several minutes. Again, not sure if this applies to other engines, but I've seen it several times on VW diesels, often caused by pitting of the aluminum head due to infrequent coolant changes. -- Shawn Wright shawngwri...@gmail.com S/V Callisto, 1974 C&C 35 https://www.facebook.com/SVCallisto
On Wed, May 13, 2020 at 9:11 AM Della Barba, Joe via CnC-List < cnc-list@cnc-list.com> wrote: > We have: > > Bilge from any point in the system including the water heater > Exhaust via combustion chamber > > Exhaust via raw water from an internal heat exchanger leak > > Internal leak in the water heater (yuck!) > > A leak someplace in the manifold that dumps into either the intake or > exhaust > > A leak someplace in the recovery tank > > > > I think we got to 6 now. A pressure testing cap for the heat exchanger > should find many of these. I cannot emphasize enough to CHECK THE OIL. I > know more than one person who was puzzled by an inboard engine GAINING oil > and then soon after was buying a new engine. It was water in the crankcase > floating the oil up higher. If you run it like that the oi whips up into > brown foamy goo that does not lubricate well at all. I had one such engine > and we drained the water out each day until it died for good. Crap > Mercruiser engine L > > > > *Joe Della Barba Coquina C&C 35 MK I* > > *www.dellabarba.com <http://www.dellabarba.com>* > > > > > > > > > > *From:* CnC-List [mailto:cnc-list-boun...@cnc-list.com] *On Behalf Of *Marek > Dziedzic via CnC-List > *Sent:* Wednesday, May 13, 2020 11:53 AM > *To:* cnc-list@cnc-list.com > *Cc:* Marek Dziedzic <dziedzi...@hotmail.com> > *Subject:* [EXTERNAL] Re: Stus-List Loss of coolant > > > > Theoretically, one more place - water heater (if fitted). > > > > Marek > > > > > > -------- Original message -------- > > From: "Della Barba, Joe via CnC-List" <cnc-list@cnc-list.com> > > Date: 2020-05-13 10:35 (GMT-05:00) > > To: cnc-list@cnc-list.com > > Cc: "Della Barba, Joe" <joe.della.ba...@ssa.gov> > > Subject: Re: Stus-List Loss of coolant > > > > It is only going one of three places – the bilge, the exhaust, or the oil. > > Check the oil for coolant contamination ASAP and check the exhaust for > excess steam and/or white smoke. The bilge should be obvious ;) > > > > > > *Joe Della Barba* > > *DCSI* > > *410-966-7255* > > > > > > > > *From:* CnC-List [mailto:cnc-list-boun...@cnc-list.com > <cnc-list-boun...@cnc-list.com>] *On Behalf Of *Bill Coleman via CnC-List > *Sent:* Wednesday, May 13, 2020 9:34 AM > *To:* cnc-list@cnc-list.com > *Cc:* Bill Coleman <colt...@gmail.com> > *Subject:* [EXTERNAL] Re: Stus-List Loss of coolant > > > > Not in a 3JH4E, but I did in my Olds Custom Cruiser Wagon, with one of > those 350 Modified Diesel Engines. Those were not up to the task which I > knew going in, but I just loved that car. It was common for warpage at the > head gasket, I think the coolant leaked into the oil, tho it may have gone > out the exhaust, I don’t remember anymore. I just remember loosing the > coolant, and several hundred dollars. > > > > Bill Coleman > > Erie PA > > > > *From:* CnC-List [mailto:cnc-list-boun...@cnc-list.com > <cnc-list-boun...@cnc-list.com>] *On Behalf Of *Glenn Henderson via > CnC-List > *Sent:* Wednesday, May 13, 2020 8:47 AM > *To:* cnc-list@cnc-list.com > *Cc:* Glenn Henderson > *Subject:* Stus-List Loss of coolant > > > > My Yanmar 3JH4E has been slowly leaking coolant. I motored for 14 hours > and it lost 5mm of depth in the reservoir. The reservoir is approximately > 4" DIA. I checked thoroughly for visible signs of leaking and found none. > Has anyone had this experience? > > > > Glenn Henderson > > WeGo > > C&C 41 > > > > _______________________________________________ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > >
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