hey guys im still pretty new to my car so i was wondering when the car is shut off are the radiator fans still supposed to run?

I had no clue if they were supposed to or not but when i put the key back in the ignition and switched it to the on position the fans stopped...

im just a little paranoid because i just got the MSP16 reflash today and today was the first time i noticed the fans comming on after the car was shut off.

 

Normal, let it run as long as it wants to.

 

thanks bro!

 

yeah but the problem wit that is the fan is known to kill the battery also because its using battery power that mean more work for your alternator on start up and can also go out. but like you said you put the key back in and shuts off right? click it to on possition and back to off it will stay off.

 

yup they are supposed to run after a hot drive or ambient T

They run for a half minute after driving to work for me at summer temps (100-110F)

 

yeah i let mine run now cuz i upgraded my battery. puse they need that cool off time in cali weather.

 

Yes, its a cool down procedure after hot summer temps

 

I would advise against "fooling the fan". This happens for a reason -- when the engine needs to shed heat. Better to spend a bit of battery power here.

If I'm parked at home I will pop the hood to help it out. Regardless, I let the fan run until it decides to shut off. I've had times where it seemed to go on for 20 minutes (didn't really time it).

Not a major problem for a healthy battery; iirc, the fan is pulling something like 7 amps. A 20 minute run is only about 5% discharge for 45 amp-hour battery. You get that much discharge just letting the car sit for a couple of days.

If you're driving in extreme heat, you can assist by spending the last 10 minutes or so driving at low power and with few stops, and AC off. This will help bleed heat more effectively than the fan run-on. I know it's not always possible but the general idea is not to flog it right before shutdown in high temps. And it's always a good idea to kill the AC at least a couple of minutes before you shut down. It helps dry the evaporator coils and avoids mildew growth and "smelly AC syndrome". The more humidity you have the more this last bit applies.

 

Just remember this :

The fan turns itself on for a reason ...