Fan Coming On


Registered User
Hi folks - wondering if anyone has any thoughts on this.

The fan has recently started to come on after I stop the car. It is a 2012 A5 Sportback Sline. I have this A5 3 years and this has never happened. Now when I drive 40km to work, stop the car, get out and lock it, the fan is staying on for 5 minutes.

During the summer there was one or two really hot days where the fan stayed on after I stopped the car. I thought with the hot weather this is ok, it made sense. But today the temperature was just 14 degrees.

Nothing else is jumping out at me:
  • Coolant level is fine.
  • Temperature gauge is bang on center before I turn off engine.
  • No warning lights on dash
I used to have VAGCOM but not anymore, so I will need to get someone to check for error codes.

I think as sensor can go faulty without showing up warning light on dash right? And possibly without any error codes when you hook up VAGCOM? So I guess the quick thing to check is replacing the sensor? Is it just the coolant temp sensor?

I guess the other thing is that the fans could have gone faulty? But I am not sure this would cause the behaviour I am seeing now?


Registered User
Is it a Diesel? mine used to do this after a DPF regen, as the dpf got more knackered i found it cleared more often(every other week, used to do it rarely) untill I had the DPF delete.


Registered User
other thing is coolant age, fan coming on after the car off is normal, engine temp prob fine but maybe the coolant is above the threshold (not over heating) so it is cooling the engine based on the coolant tempt reading after switching it off, no harm in a coolant flush if it has been a while :)


Registered User
DPF regen. if a diesel... Used to do it quite often on my A3 TDi. Does it happen every time or only every few stops?