Electric fan when the engine is off or on?

[oil pan 4]

Running the fan with the engine off and no coolant flowing doesn't seem like it will do much.

I can run fans and cool my engine off because I have a electric coolant pump and some times my diesel gets a little too hot while sitting at stop lights in the middle of summer.

[RobertISaar]

Originally Posted by oil pan 4

Running the fan with the engine off and no coolant flowing doesn't seem like it will do much.

this would be my reason not to. there might be a small thermal siphon effect going on if the water pump isn't spinning to move coolant, but otherwise it is entirely stagnant. what is in the radiator would be cooled, but nothing else. at that point, the air already moving through the radiator from coasting is probably more than sufficient to cover that task.

[redpoint5]

...which brings us right back to running the fan when the engine is running, regardless of whether or not someone does an alternator delete. I maintain that the fan should come on when the coolant temperature is too hot, and turn off when it is in the ideal range. That means leaving the fan to control itself.

[dirtydave]

Originally Posted by RobertISaar

this would be my reason not to. there might be a small thermal siphon effect going on if the water pump isn't spinning to move coolant, but otherwise it is entirely stagnant. what is in the radiator would be cooled, but nothing else. at that point, the air already moving through the radiator from coasting is probably more than sufficient to cover that task.

Originally Posted by redpoint5

...which brings us right back to running the fan when the engine is running, regardless of whether or not someone does an alternator delete. I maintain that the fan should come on when the coolant temperature is too hot, and turn off when it is in the ideal range. That means leaving the fan to control itself.

I don't let the fan control itself because It doesn't work! Not sure what the real issue is but I'm cheap / lazy and just used a quick fix. simple switch on the dash.

I guess most people agree to let it run when the engine is running. And when its getting hot.

I was considering an alternator delete, but I'm not going to unless I can get another bigger / better battery and a better solar panel for free / dirt cheap.

[cRiPpLe_rOoStEr]

Originally Posted by dirtydave

I was considering an alternator delete, but I'm not going to unless I can get another bigger / better battery and a better solar panel for free / dirt cheap.

Even if you'd get those, I'm not sure if the full alternator delete is really that great. I'd rather try to set it to also act as an auxiliary motor in a similar way to the BAS-hybrid layout.

[dirtydave]

Originally Posted by cRiPpLe_rOoStEr

Even if you'd get those, I'm not sure if the full alternator delete is really that great. I'd rather try to set it to also act as an auxiliary motor in a similar way to the BAS-hybrid layout.

Yeah I don't think I will do that project because the ROI is not going to be seen in the remaining life of the car..