hey everyone, I was having an overheating problem on my 86 f250 with a 460 in it. the previous owner had a flex fan so i just installed a fan clutch along with a rigid fan. What im seeing though is my Fan is still running 100% of the time. Did i get a bad fan clutch ? It's by no means hot enough it should be kicking in at start up. The outside temp today is like 10. Im not really sure where i could have screwed this up i bolted the fan onto the clutch and the cluth onto the pully. thanks for the help
forgot to mention. The fan will turn without the engine running but not as freely as it seems it should takes a few pounds of force to move it

 

The fan will always turn with the engine, that's normal.
There should be some drag in the clutch.

 

Ok so the fan is turning 100% of the time but with a slower speed then when its fully engaged Thank you.

 

i have always tossed the fan clutch and ran the fan with a fan clutch eliminator and with a fan with as many blades as possible ! flex fans are worthless as they dont pull enough air through the radiator !! check your radiator to see if it is partly clogged !!

 

well my problem at the moment is over cooling in the winter. i had the rigid fan on this last weekend and drove about 180 miles the engine temp never hit 130 so i need that fan to slow down and stop sucking so much air thats why i put a clutch on it this weekend and wasnt aware that it would still be turning the fan but at a slower rate i guess. if this doesnt work i'll have to play around with cardboard inbetween the ac condensor and the radiator i guess thanks for the help

 

Your thermostat is not working.
Either it is stuck open or bypassing somehow.
How do you know exactly what temperature the coolant is?
Stock gauges/senders can be misleading.

It is not the job of the fan or the radiator to maintain correct engine temperature.
Only to shed excess heat.
In fact, the fan is only effective when the vehicle is slow or stopped.

It is only 10 degrees now. What will happen when it gets really cold?

 

your thermostat , do you have one in there ? also get a thermometer and stick it in the radiator while it is running and see what it says ! do you have water flowing through the heater core ?

 

I agree with this, check the thermostat, I would bet it's stuck open.

The thermostat's job is to maintain the correct engine temp, and it uses the fan and radiator to do this when it gets too hot. Too cold and the thermostat shuts off basicly stopping coolant flow.

This depends on which fan you have.

Flex Fans are only effective at low engine RPMs. After the engine is reving the fan blades flexs flat and will no longer pull any air through the radiator. This can be detrimental if you are pulling a hill at low speeds at higher engine RPMs.

Centrigfugal Clutch fans (no spring on the front) are effective at any engine RPM speed. They do not flex flat, and will pull the same amount of air, at idle as it will with the engine reving. This is great for pulling a hill as low speeds and higher engine RPMs will not effect it at all. Infact the faster the engine turns the more air it will generally pull, to a point. Unlike Thermastatic Clutch fans, they are always partially engaged. They are neither fully engaged, or disengaged and will turn basicly the same at any RPM or at any temp level.

Thermastatic Clutch Fans (they have a spring on the front) are effective only when the temperature warrants it. When the engine is cold, the clutch fan is disengaged and will only turn freely, not pulling any air at all or at the very least the bare minimum. This gives the engine the most horsepower, as it's not using the horsepower to turn the fan. When the temps rise, the spring on the front of the clutch fan will engage, and the fan will turn faster. When the engine is hot, the fan clutch will fully engage and be full on, giving the most cooling capacity the fan can give. Engine RPMs or speed will not effect this fan, as it's controlled by temperature, unless the fan is fully engaged, then the faster the engine turns, the faster the fan turns.

 

You are correct 81-F-150- Explorer.

These trucks (86-87 460) have a thermostatically controlled clutch.

I would have been more clear in saying that at highway speeds the fan engaged, or not, has little extra cooling effect given that there's already 65mph airflow through the radiator.