Recently my radiator fans started coming on and staying on the entire time I am driving, and they continue for a few minutes after I stop. I know it is normal for the fans to stay on for a short while after turning the car off if the coolant is hot, but I've never experienced them staying on every minute I am driving.

Could this be caused from old coolant? I am going to change out my coolant since I haven't done that in a while.

Thanks in advance for any info

 

It is a common problem for the thermosat to stick (in any position) for the 4.0 cars, chances are your thermostat is stuck more closed than open. If you still have your stock thermostat, better to swap it quickly, cheap and easy.

 

Is there a better aftermarket thermostat to swap it out with?

 

I got an OEM 185 degree thermostat and swapped out the old and replaced the coolant.

My fans are not coming on anymore - the old thermostat was the problem.