Problems with 25D engine cooling

[Dan Kaplan]

I'm wondering if I have a water pump or impeller problem. Yesterday the "coolant" light and alarm came on just as we were leaving the dock. I noticed that water was not coming out of the exhaust, so we returned tto the dock. When I bought the boat (just over a month ago)it had to have an impeller replaced in the middle of the survey. So I'm wondering whether anyone else has had coolant problems with their Yanmar GM1. Please let me know.



dankanchor@msn.com

[Duncan Maio]

Some likely sources of the problem: (a) clogged raw water intake - barnacles, zebra mussels, bottom paint on the strainer (my CD27 has fairly small holes on the through-hull); (b) closed raw water seacock; (c) failed impeller - I have heard several accounts of impellers failing almost immediately after intsallation.

Let us know what it turns out to be.

Duncan Maio
Remedy
CD 27 #37



dmaio@att.net

[Jim Jamieson]

I had the same problem earlier this season. New impeller in the 1GM and the overheat lamp went on after 9 hr of engine time. Blades had separated from the metal piece that goes over the shaft. Put a new wone in and no problems after 50 hr. They should last 1000 hr acording to Yanmar's manual I recall. This was a common problem with one lot of impellers according to a post from the UK to me.
jim



james.jamieson@yale.edu