2014 V8-380-CD.
Closed cooling.
My marina gets to less than 2’ of water at low tide. When docking yesterday, I had my first overheat event after expecting it to happen someday after all these years of docking in shallow muddy water.
Alarm sounded while at idle speed and I immediately saw the issue, 190F on temp gauge. Shut it down, waited a few seconds, re-fired it to attempt to get water moving, did that a few times, and temps finally reduced to normal range of 160-162f.
Back at marina today, I idled it and temps would rise to 165f and then drop back down to 160ish when thermostat would open. Engine running smooth whole time.
Took it out and above 3k rpms temp would just continue to climb. I backed off when it would get to 170f. Below 3k rpms it would run at normal temp.
Back at marina I inspected impeller, expecting to see damage, but all was well. Housing was unscored. I swapped in a new impeller anyway.
Drained the heat exchanger by removing the bottom plate and mostly clear water poured out, some minor plant debris, too.
Inspected the intake ducts on the outdrive with boat out of water, and they looked clear.
Buttoned it up and put it back in water, and same temp issue is happening.
Motor always runs correctly, no evidence of combustion product in the coolant or oil, which would suggest intact head gaskets.
On a car, this would suggest a clogged or damaged radiator, as the thermostat is opening and relying on heat exchange to happen.
Suggestions on what to try next? Flush the exchanger?
Closed cooling.
My marina gets to less than 2’ of water at low tide. When docking yesterday, I had my first overheat event after expecting it to happen someday after all these years of docking in shallow muddy water.
Alarm sounded while at idle speed and I immediately saw the issue, 190F on temp gauge. Shut it down, waited a few seconds, re-fired it to attempt to get water moving, did that a few times, and temps finally reduced to normal range of 160-162f.
Back at marina today, I idled it and temps would rise to 165f and then drop back down to 160ish when thermostat would open. Engine running smooth whole time.
Took it out and above 3k rpms temp would just continue to climb. I backed off when it would get to 170f. Below 3k rpms it would run at normal temp.
Back at marina I inspected impeller, expecting to see damage, but all was well. Housing was unscored. I swapped in a new impeller anyway.
Drained the heat exchanger by removing the bottom plate and mostly clear water poured out, some minor plant debris, too.
Inspected the intake ducts on the outdrive with boat out of water, and they looked clear.
Buttoned it up and put it back in water, and same temp issue is happening.
Motor always runs correctly, no evidence of combustion product in the coolant or oil, which would suggest intact head gaskets.
On a car, this would suggest a clogged or damaged radiator, as the thermostat is opening and relying on heat exchange to happen.
Suggestions on what to try next? Flush the exchanger?
