Electric fan noise -- what is it?

[Bill Littlefield]

When I'm pulling my boat on a hill (light load of 3500 lbs), I sometimes hear an electic fan kick on and run for a couple minutes. I don't see any change in my engine water temp. The fan sounds like it turns some serouse rpms.



What is it? What set points trip it?



Thanks for the hints.

 

[Missouri Mule]

Bill,

I think you are hearing your fan kicking in.

Don't remember exact figures for fan clutch to engage but when it does it is noisy.



What are your temps are you running when fan goes on?

 

[Bill Littlefield]

Missouri Mule,



Thanks for he reply. It sounds like an electric radiator fan but I didn't think mine was electric. Maybe just ignorance on my part.

The interesting things is that under normal operation, my temp gauge ramps up to about 200 degrees F, the thermostat opens, and it drops quite rapidly to about 140 (not sure) and then starts ramping up again. This cycle takes less than 5 minutes. When I hear the fan noise kick on, it always makes me check the temp qauge. It's never above 200 and it doens't seem to drop much if any while the fan is running or when the fan turns off. This is what confused me. I expected to see the gauge drop to some point and then hear the fan kick off if it is a radiator fan. Am I missing something??? This made me think maybe it had something to do with the AC or intercooler??? Something other than radiator water temp???