I'm looking for advice on a situation that arose yesterday. I have a 34 with a 3GMD diesel with raw water cooling. I motored for about 45 minutes at 2000 rpm and then shut the engine down. Everything was running smoothly. The temp gauge showed the normal 100 degrees and I could hear water from the exhaust. I sailed for about half hour but then lost the wind and turned the motor on. The high temp alarm stayed on and the gauge showed 140 degrees. I shut it down and checked the water filter, which looked fine. I tried starting it a couple more times with the same result, so I sailed back to my harbor. When I went to start it, everything worked fine again, and I ran the motor for a good 30 minutes with no issues. The gauge stayed at 100 the whole time and no alarm.
I initially thought it might have been the impeller (which is about 1.5 years old right now), but when the problem arose I didn't check for the sound of exhaust water. Since it was working back at the harbor, I don't think the impeller was bad. I'm starting to think that the sending unit malfunctioned and then reset itself somehow but that's never happened before. I'm not sure what temp triggers the high temp alarm and whether the same sending unit goes to both the alarm and the gauge. Am I missing something obvious? Were there other steps I should have taken to diagnose it? I was of course concerned to run the engine for long if it was overheating. What next steps should I take, since everything seems fine right now. Thanks in advance for any help. Al Serrato C & C 34 Fidelity San Francisco Bay _______________________________________________ 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
