Driving with out a fan?

[dernst]

I have a 4.0 A/T radiator and my 2.9 runs very cool. If I use a 180 thermostat, it will stay at exactly 180, even on 100*+ days. It takes about 15 minutes to warm up. (I drilled about a 1/8" hole in the T-Stat to promote flow when it isn't open. This slows the warm up time).

In the winter when the temps are around freezing, I was thinking about removing the fan and fan clutch to increase fuel mileage. I was guessing that this wouldn't affect that motor temp unless I was doing something that will generate lots of heat. If I try this, I will monitor my two gages closely.

?? If I remove the fan, will it affect the water pump in a negative way?

I've read the argument for years about replacing mechanical fan with an electric one. I was thinking about installing an electric fan for the winter for the occasional times where additional cooling is needed. I understand that when a fan is needed, a mechanical fan with a clutch will be more efficient. I'm guessing that in the winter, I could get by with no fan at all-- especially when the vehicle is moving and the temps are low.

I'm guessing that the gains from not using a fan at all will out weight the losses of occasional use of an electric fan. After all, it does take energy to move the mechanical fan.

 

[holyford86]

I would run something in there. I have worked on a 2.9 powered b2 without a fan but its a race truck in a tough truck competition and we had to weigh whether we wanted a hole in the radiator or no fan, we chose no fan. For DD use I would have something in there. if you are worried about it not getting up to temp make some sort of winterfront for it.

 

[MAKG]

By all means, go ahead and try.

And let us know if your 2.9L survives its first drive-thru.

Of course it's a good risk for a mileage savings so small you can't even measure it.

 

[Wicked_Sludge]

leave the fan on.

you mechanical fan is mounted on a viscous clutch that is thermo regulated. this means that when your truck is cold, the fan clutch disengages and the fan is freewheeling...thus it doesnt draw any power (and therefor fuel) from the engine, and its moving a negligible amount of air. a properly working clutched fan can be held stationary with one finger...if this gives you any idea on how little energy the fan is using when the clutch is disengaged.