It is pretty hard to judge the flow rate coming out of the exhaust by eye, and I have been falsely lulled into thinking that all was well in that department on more than one occasion. It absolutely could be a problem with your thermostat or temperature sensor as others have suggested, but it is far more likely to be a problem with the rate of raw water flow in my experience.
In addition to cleaning out the strainer you should check for a partial blockage at the intake or between the intake and the strainer screen. A small piece of twig can get in there and slow things down without stopping the flow completely. It is fairly easy to disconnect the hose from the filter and flush back out through the through hull using a dock hose. The one place that this does not get is passage in the strainer housing itself, and sure enough I had a piece of wood get stuck in there one time. Took quite a while to find it, and in the meantime I bought a new thermostat and a new temperature sender. About the only common way to get debris downstream from the raw water strainer is if part of the pump impeller breaks off. It should be checked if cleaning out the strainer and the raw water system that leads to it does not fix the problem. Steve Thomas C&C27 MKIII Port Stanley, ON ----- Original Message ----- From: Peter Delean via CnC-List To: cnc-list@cnc-list.com Cc: Peter Delean Sent: Tuesday, September 08, 2015 12:33 Subject: Stus-List Diesel water alarm question Yanmar 2GM-15 After warming up the engine, motoring out of the marina and into the bay (about 5-10 minutes of moving) the WATER light and alarm came on. I checked out the exhaust, there was water coming out as it should. I eventually shut off the motor and sailed for a bit. After sailing same routine: engine on, 5-10 minutes into the ride back to port the WATER alarm and light came on. The impeller was new in July, and had maybe ten hours on it. The cooling water comes from under the boat then passes through a filter before heading to the motor. It appears to need to be cleaned. (Bottle looks grungy). I could not locate a place to check the engine coolant. I wanted to make sure that that was topped up. While I was away, the marina personnel ran the motor at idle for a minutes, did not see an alarm, and assumed all was well. They did not check the filter or the coolant as far as I know. I am assuming the water pump/impeller is good as it is new. Any other things I should be considering? Peter Delean Drifter II, 30-1 Penetanguishene, ON ------------------------------------------------------------------------------ _______________________________________________ Email address: CnC-List@cnc-list.com To change your list preferences, including unsubscribing -- go to the bottom of page at: http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com
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