Re: Onan shuts down under load without shutdown codes
toggle quoted messageShow quoted text
Guessing from thousands of miles away.
The shutdown is because the block is too hot.
Normally it should be about 80C under load and warmed up. However, the exhaust elbow is at the correct temperature. My guess is that the coolant is not circulating as it should, and therefore not cooling the block. The seawater side seems to be functioning correctly, but not the coolant side. That could be a number of things including the coolant (captive) pump, a loose fan belt on the captive pump, a stuck thermostat, an obstruction somewhere in the coolant path.
I would start with the thermostat. If you do not have a spare, you can temporarily remove it until you have one. You will likely need some PermaTex-type gasket material because those gaskets usually tear.
On Fri, Aug 14, 2020 at 1:28 PM Mark Pitt <mark_pitt@...> wrote:
I installed a new flow sensor that I had in my spares. I also replaced the impeller. The existing impeller did not look too bad but it appeared that one vane had adhered to the impeller hub, perhaps from overheating. I opened the cooler and found no obstructions. I also examined the hose segments from the raw water pump to the cooler and found no obstructions.