1GM10 temperature alarm

[Impaler]

Does anyone know at what temperature the alarm sounds on a Yanmar 1GM10 on the cooling water system. Mine went off, I know why, just wondered what the temperature would have been. How much time do you have to shut it down before she's toast?

 

[KenMcCulloch]

Not all that hot I think. I started mine with the water intake off (don't ask, it's the only time I've ever done that) just on the way to the crane berth in December. I shut the engine down, turned on the seacock and restarted; the overheat alarm shut down less than a minute later. That despite what I have now discovered was a very restricted flow of water from the sea to the impeller.
My main worry was for the exhaust hose but it seems to be fine, ditto the impeller. You would need to run a wee engine like that for a good few minutes with no cooling water, so long as the oil was circulating, before doing more than minor damage I think. Despite their detractors they are quite robust little machines.

 

[smeaks]

one thing to watch for is if the alarm goes off and the engine is hot then, if safe do so, let the engine cool before opening the sea cock (if indeed that is the fault) otherwise you will be flooding very hot water ways with very cool water..... obviously if you are unable to stop the engine due to manouvering constraints its a judgement call...

I have had the alarm go three times one was a duff impeller and the other two (i am embarrassed to say) were because I did not open the sea cock! - what a nugget - but on two different boats.

 

[steve28]

if the engine is dry the alarm goes off when the engine is considerably hotter. It relys on the water over the end of the sensor to activate.
the 1gm raw water sensors are 65 degrees +- 2% activate
fresh water sensors are 95 degrees +- 2% activate


steve

 

[Impaler]

Thanks all.