gaborkarak

Hi
While doing regular checkup on my car, I noticed that both radiator fans (left and right) are on when the engine is on even though the A/C is not running. Is this normal? Can somebody check on their car and let me know whether this is a minor issue that needs to be resolved? No faults on the dashboard btw.

raylor4

It's my understanding that the radiator fans come on when the engine coolant needs to be cooled and/or the A/C is on. Anyone else?
Ray A.

pamiboy

That's exactly what my understanding is.

gaborkarak

So I tried turning the A/C on&off but nothing indicates it operates except for the cold air. No clicks, no fans starting/stopping... Hmm something is wrong here?

vlad_a

Are you running in windshield defrost mode and the temp is above 0C? Press the fan OFF button and see if anything changes.

gaborkarak

Temp is around 60-70F (California), Internal temp set to about 72-75 normally with no A/C, even when the fan is on OFF, both engine bay fans are running. (Not in windshield defrost mode.)

SteveCraig

Electric t'stat will open & close based on cooling requirements of the engine, turning the fans on & off.
City driving & idling will bring coolant temps up with very little airflow across the radiator.
Highway driving tends to cool much better as substantially more air crossing the radiator.
Ambient air temps will play a role here too.

Vehicles sold in different locations may see different t'stat installed as new. I cannot verify this one.
I do know a car sold in The Great White North, along the Eastern coast will see a substantially lower average temp. compared to a car destined for California.

Clutchless

To see if they are ever off, wait until your car has been off overnight, then before you start it go through the menus to turn off the A/C, then open the hood and start your car. Your fans should be off since the motor is cold. I would only worry if the sensor failed and your car overheated because the fans failed to turn on! I think everything is operating as designed.

gaborkarak

So, just to clarify... Car has 'slept' overnight, I go and open the hood in the morning, no A/C, no windshield defrost, internal fan is off, start the engine and both fans are on in the engine bay. Can somebody validate whether this is happening on other RX's? Clutchless, maybe you could check this for me?

I'm not worried, but having fans on all the time is unnecessary wear on components, prolongs engine warm up time (therefore increasing engine and oil wear) and frankly, I just don't like broken things...

Clutchless

I will try and check soon. I do not drive mine that often. I do not think the fans being on would increase warm up because no cold coolant from your engine flows through the radiator because it is blocked until the engine warms up and the thermostat opens to allow coolant to flow through the radiator and maintain the correct temperature.

lexus114

you had me curious about this fan thing so this morning i popped the hood and checked mine. the fans were both off.

vlad_a

It is entirely possible that a relay is stuck. Is the drivetrain still under warranty?