2nd Gen Non-Engine/Transmission Fan kicks in when I take overdrive off?

[dodger22]

I posted the following in the Hauling and Towing forum and got no response, maybe somone here can help?



Just completed a 9,000 mile jaunt across to the West coast and back through Canada pulling a 10,000lb 5'er.



I have noticed on this trip that the engine temp is running a little higher than my previous trips and that when I kick the overdrive off, the engine fan will kick in for maybe 15-20 seconds and then shut off. I know the temperatures have been high this year but they were high last year also and I didn't encounter this condition then.



Anyone else encounter this? Is it something I should be concerned about?



The truck has just turned 45,000 miles and for the whole trip I averaged just over 15 m. p. g. That's imperial gallons, eh?



Thanks,



Richard

 

[B.G. Smith]

Fan clutch

Well for one thing, you are getting good fuel mileage(compared to mine). You say "when I kick the OD off", are you turning the OD off with the button or kicking it off by accelerating or climbing a grade? If the latter is the case, the trans. is going back into third gear and the torque converter is unlocking and then re-locking after a bit. Are you sure this is not what you are hearing? There is no reason for the fan clutch to react to the OD kicking off except the engine RPM's go up. As for the higher temps, it could be trash in the AC condenser restricting air flow, could also be the radiatior dirty inside but I doubt that on a 01. I would pull and inspect the thermostat as that has been a known problem with our trucks(I have changed three in mine) , on one of mine one of the straps broke on the yoke. On the other two, the rubber seat came off the valve. Let us know what you find. bg

 

[illflem]

If Richard is going out of od with the accelerator the trans is kicking into 3rd unlocked. Running with TC unlocked heats things up real fast. Better to use the od off button.

 

[dodger22]

Thanks guys for your replies, when I refer to "kicking off the od" I am actually using the od button. I am planning to change out the anti-freeze and also the thermostat at the end of the summer.



Richard