cooling water, not!

[John D LeClare]

I lost the cooling water to my yanmar sve 8 for about fifteen minutes today. Anything I should check other than the impeller?thanksJohn

 

[Paul Akers]

Strainer

If you have a strainer, make sure that it is not clogged. Or go back one step to the raw water thru-hull. Shut the seacock, disconnect the hose and try opening the seacock for a second. You should get a good stream of water. If not, there's a clog at the thru-hull.There are a couple of things that you can try. With the seacock open, stick a stiff wire into the seacock from inside the boat and try to free the plug. Or you can do the sane with a high pressure water hose nozzle. I've even use my dinghy inflator foot pump to push backpressure into the seacock. I've always been successful (knock wood). Usually it's just eel grass or seaweed.

 

[Jim Russell]

And do replace the impeller

Since you've already mentioned the impeller, you're on the right target. I did something similar for about the same time and found the impeller brittle and needing replacement. You might want to top the closed loop coolant off should you have inadvertently boiled some over. Probably did not occur unless the engine was already quite warm.

 

[John D LeClare]

update on cooling water

After replacing the impeller(no clogs at thru hull) I get good flow only if I prime the system first. I disconect the hose into the thermostat and apply a vacume untill I have a steady stream of water. I had to do this in the past with the old impeller also. Could this be an air leak some where? Once it is running every thing is fine.John

 

[Paul Akers]

Heat Exchanger?

Maybe a clog in the hose from the raw water pump (impeller) to the heat exchanger. Or possibly scaling inside the heat exchanager causing a blockage.Gotta look a step at a time.

 

[Paul Akers]

Ideas, Gordon?

NM