Coolant Smoke or more?

[Tally Ho]

Mine exits below the waterline and has an exhaust loop up to the height of the deck. This ensures no water ingress.

As long as the hose doesn’t come off the fitting....maybe that is the OP was referring to.

Greg

 

[Ralph Johnstone]

As long as the hose doesn’t come off the fitting....maybe that is the OP was referring to.

Guess you've got to start trusting something somewhere.

Exhaust hose double clamped with 100% SS hose clamps, in a low vibration area, just where that hose is attached to the heavy FG nozzle glassed into the hull. Sorry, no picture for this. I replaced the entire exhaust hose about five years ago and almost killed myself getting it off the hull fitting with a heat gun, a wrench, and NO HOSE CLAMPS !

Maybe that and a little ...............................

 

[Tom J]

Hey,

I never close my through hulls. The engine raw water intake only gets closed when I store the boat in water for the winter (after I winterize the engine). The head intake is always closed (I use fresh water in the head). The holding tank direct discharge is always closed. The sink drain is always open. I exercise the seacocks at least once a year. The seacocks in are awkward to reach places and there is no way I'm going to open and close them each time I use the boat.

Good luck! My seacocks are closed every time I leave the boat. All of them. And I live aboard every season. Yes, they are awkward to get to, but diving 20' to get to my boat is more awkward.

 

[niner_gang]

Change the engine oil: not related to your smoke but heat is the #1 enemy of oil viscosity. Have you inspected the raw water pump impeller? It is very likely that rubber impeller vanes may have broken off when the pump is ran dry even for a few seconds. Broken impeller vanes will lead to further overheating as the pump will loose capacity to move water and the broken pieces of the vanes may clog cooling passages. Give your raw water discharge port a quick glance to see if water is running through the system. Your exhaust port is located below the waterline at the stern of the boat, with the engine running should should be able to see turbulence in the water confirming there is water flow. Unless you had observed it prior to the overheat you may not have a point of comparison to determine if the flow is normal or diminished. A serious overheat could damage an engine but these Yanmar engines are pretty hardy. just start by insuring proper water flow and then take it from there. If the impeller vanes are broken you need to look and account for every little piece as in the future that llittle piece could be the cause of another overheat. Good luck. We have probably all done that but a trick to avoid repeating it is, "whenever you shut the seacock hang the boat keys on the valve lever".

Thank you!

 

[niner_gang]

Great forum, thanks for all the help. It’s feat to know there’s a place to get real world advice.

As an update, went down, refilled the heat exchange tank, had lost maybe half a gallon? And recovery tank was empty also. Filled that also. Fired right up. Had a mechanic take a look at the impeller, said it looked good and coolant was circulating as expected. Motored for an hour or so, had no issues.

 

[Ralph Johnstone]

but diving 20' to get to my boat is more awkward.

.................................. and drying it out, even worse !

 

[Hello Below]

.................................. and drying it out, even worse !

@Ralph Johnstone, I bring this to your attention.

Dehumidifier Suggestions

 

[Ralph Johnstone]

As an update, went down, refilled the heat exchange tank, had lost maybe half a gallon? And recovery tank was empty also. Filled that also. Fired right up. Had a mechanic take a look at the impeller, said it looked good and coolant was circulating as expected. Motored for an hour or so, had no issues.

Glad you are back in business with no apparent harm to you or the boat .

Please realize you are not out of the woods yet as there are still a number questions to be answered which others have posed. The smoke, the loss of coolant, and empty overflow tank should NOT have happened simply as a result of the overheating. I suspect some form of damage occurred as a result of the overheating.

Best of luck and keep in touch.

 

[smokey73]

Hey,

I never close my through hulls. The sink drain is always open.

Do you leave your boat in the water over winter? (Probably not in MA) If you do, assuming the sink drain through hull is below the waterline, think about this. You run some fresh water from your fresh water tank into your sink and it only drains to the water line level. (basic liquid behavior) Now you get a quick very cold night below zero. If the fresh water freezes it might just rupture the hose or the fitting at the through hull. Maybe not too much of a risk but in the winter, why risk it? What kind of hose runs to the sink drain through hull? Rick Stidger has an interesting experience with this so I replace all the cheap sink drain "bilge flexible rib" hose with real hose rated for below the water line. Is your hose there suitable for below the waterline service. Bilge hose is not!

I once drove 4 hours to look at a Hunter 37.5 on a fresh water lake in Tennessee. When I got there the boat was tied to the pier but the only thing showing was the deck above the water and the mast. It had sunk when the owner left all his through hulls open and at least one ruptured and sunk the boat. Not worth the risk to me so part of my leave the boat routine is to close all through hulls. I leave the key for the Yanmar on the raw water through hull valve to make sure I open it before I start the Yanmar.

 

[Ralph Johnstone]

@Ralph Johnstone, I bring this to your attention.

I think we're on the wrong side of the fine line which divides excessive humidity from barnacles growing on the inside of the cabin walls :