How is this Possible?

[Cadence]

Originally Posted by Kenomac

Thanks, this is exactly the same conclusion I came to earlier today after I ran the Yanmar engine for twenty minutes and watched the drip dramatically increase. I'm now just waiting for advice from the shipyard which serviced the heat exchanger. Wondering now whether it's OK to continue 300 miles further north to haul out at their yard.

Thanks again.

Ken

For 300 mi. worst case don't run the gen. without the main. You already have salt in the coolant. I hope it is as simple as an O-ring as a64pilot suggested.

I don't think 3 weeks will kill you. People have run raw water engines for years. Just flush the sh&@%t out of it.

[captmikem]

One other possibility in the event the heat exchanger proves to be good: it is possible that the heat exchanger in the hot water heater could have a slight leak, the water in the hot water tank is probably kept around 35 to 45 psi so it would only flow from the hot water tank into the engine. When the gen set is running the electric element is heating the water in the tank creating more pressure.

Good luck with it,

Michael.

[a64pilot]

I believe it is safe to assume that water from somewhere is being added at the rate that it is overflowing at.
I can't fathom what a generator could have to do with it, even if it's heating the water in the tank, that should not increase pressure, the water pump determines pressure.
Getting hot could I guess cause a crack in the heat ex in the tank to open up?

Ought to be simple to determine if its water from the tank though, turn off water pump and let pressure off by opening a sink, that should stop the water coming in if it's from the tank.

I like the idea of using a TDS meter to determine amount of salt water, but i have no idea what a TDS meter would think of antifreeze, how high?

[Cadence]

Michael's suggestion if possible, with your system, would scare the **** out of me. I would be afraid with the engine running coolant could get into your fresh water supply.
It don't take much ethel glycol to poison you.

[JOHNMARDALL]

As already mentioned, in ancient times, similar engines were cooled by seawater, with no heat exchanger, so provided that the zinc(s) are good, you should get back without too much trouble. Monitor the engine temperature (closed loop coolant) and the exhaust gas temperature (sea water open system) and shut down.quickly if either becomes abnormal (high or low) If you don't have an exhaust gas temperature alarm (cheap protection for the entire exhaust system) check the flow of water from the transom fitting as often as possible and if it's weak or non-profit existing, shut down.
Good luck
John Mardall
Vetus Maxwell Group

[Kenomac]

Originally Posted by Cadence

For 300 mi. worst case don't run the gen. without the main. You already have salt in the coolant. I hope it is as simple as an O-ring as a64pilot suggested.

I don't think 3 weeks will kill you. People have run raw water engines for years. Just flush the sh&@%t out of it.

I was mistaken this morning when I saw the water dripping resulting from the genset and assumed it was coming from the genset. It now appears as though the genset running caused the nearby Yanmar engine to warm slightly over the course of nearly two hours, which then caused the fluid to expand and slowly leak out of an already filled to the brim coolant reserve.

The two engines have no common conection at all, separate water separators and heat exchangers.

[Kenomac]

Originally Posted by captmikem

One other possibility in the event the heat exchanger proves to be good: it is possible that the heat exchanger in the hot water heater could have a slight leak, the water in the hot water tank is probably kept around 35 to 45 psi so it would only flow from the hot water tank into the engine. When the gen set is running the electric element is heating the water in the tank creating more pressure.

Good luck with it,

Michael.

You might be onto something! My wife has been complaning that the hot water has been somewhat intermittent. How would I check for this? We have been shutting down the fresh water pump each night for a few weeks now because over time, water has been seeping out of the system and causing the pump to cavitate. We've been unable to locate the source of the leak.

This is a very likely cause.... Need some help please.

[a64pilot]

If there is a leak in the heat exchanger in the water heater you can find out with a pressure test, block off one fitting of course and pressurize the other one, even a bicycle pump would work, just need a gauge and some creativity as to how to connect a bicycle pump to a 3/4" hose.

[poiu]

Originally Posted by Kenomac

You might be onto something! My wife has been complaning that the hot water has been somewhat intermittent. How would I check for this? We have been shutting down the fresh water pump each night for a few weeks now because over time, water has been seeping out of the system and causing the pump to cavitate. We've been unable to locate the source of the leak.

This is a very likely cause.... Need some help please.

Turn the pump off and run a tap until there is no pressure. See if the flow into the header tank reduces.

[captmikem]

One would be to pull the heat exchanger from the water heater and check it. A Q&D method would be to dump some red food coloring into the main cooling water">engine cooling water, turn off the FW pump and let the pressure off by opening a faucet, then run the M/E for an hour or so then turn the FW pump back on and run some hot water into a white bowl and look for any tint of red. Probably other ways but those are the ones I come up with.

Michael

[Kenomac]

Originally Posted by captmikem

One other possibility in the event the heat exchanger proves to be good: it is possible that the heat exchanger in the hot water heater could have a slight leak, the water in the hot water tank is probably kept around 35 to 45 psi so it would only flow from the hot water tank into the engine. When the gen set is running the electric element is heating the water in the tank creating more pressure.

Good luck with it,

Michael.

WE HAVE A WINNER!!

I tested the freshwater system this morning by first running the generator and watching the Yanmar overflow drip as usual. Then I shut off the freshwater pressure pump, the switch to the hotwater tank and hotwater heater, then depressurized the system; the dripping stopped within a minute or two. I dried everything off and then ran the generator for nearly an hour.... no drips. Repressurized the freshwater system, then a small amout of water began to creep out of the expansion chamber, I then turned the hotwater tank back on with the electrical power running from the genset. The slow drip was back.

Thank you very much Michael! Brilliant!

Even Nigel Calder didn't write this one in his book, I'm a happy sailor today! 'Should be able to easily fix this one myself.

https://m.youtube.com/watch?v=811kp3Of19Q

[joel383]

I know that feeling! Got mine 200 mi from shore in the Gulf of Alaska... But I won't hijack.

CONGRATS!!

[Symphony]

Congrats Capt MikeM
Congrats Kenomac
a great accomplishment, and to know that you diagnosed the problem far better than the shipyard people probably would have.
Everyone is more careful with their own stuff!
Congrats

[sartorst]

Originally Posted by Cadence

Michael's suggestion if possible, with your system, would scare the **** out of me. I would be afraid with the engine running coolant could get into your fresh water supply.
It don't take much ethel glycol to poison you.

Wow that is scary ! something I had not thought of ? Good reason to leave the pressure pump on and I don't because I had a hose pop off on a long motor sail only to find I had no water and a burned out pump but the bilge was nice and clean

[Kenomac]

Originally Posted by sartorst

Wow that is scary ! something I had not thought of ? Good reason to leave the pressure pump on and I don't because I had a hose pop off on a long motor sail only to find I had no water and a burned out pump but the bilge was nice and clean

It's not that big a deal really. The water can only leak out in one direction towards the engine coolant system due to the water pressure. Even if a minute amount of anti freeze was to enter the hot water system, we only use hot water for showers and washing, no cooking. Looking back, the problem has very likely existed for over three years, but I just accidentally discovered it yesterday.