Hi. Have not experienced that problem. Reducing revs as quoted would reduce the coolant temperature very slowly and in the short term the temp may even go up a little due to the huge thermal mass of the engine and reduced coolant flow, even if your thermostats stayed fully open. Over what time did the temp reduce to 40? On mine, 40 is the minimum marked temperature on the gauge so probable reads that at ambient anyway so much more likely there is a connection/voltage problem at low revs.
Temp reduces to 40/50c in about 10 minutes at 1500rpm Whereas previously it would stay at 80c. Leaving it to idle from cold it has never reached temp, only ~60c after an hour. I did think it warmed up slower yesterday than usual, running at 3000rpm temp usually rises quite quickly and runs up to 85c+ before dropping back quickly when the thermostat opens. Yesterday it just slowly reached cruising temp without any noticeable drop back as the stat opened. I’ll pull the stats and test when she comes out on October, no great harm being done at the moment.
Back out today and similar story, by the time I’ve tied up to my swinging mooring temp is at around 50c. Wouldn’t be so bad but I’m spending MUCH more time at displacement speeds since diesel almost tripled in price ?
Knowing my luck I’ll probably sink the bugger. I’ll wait until it’s out, I know it’s the fresh water side but…..winter is coming ?
