Fan that turns on after shutting car off

[Reborn_]

I have an 07 Z4M. I've noticed over the years that sometimes, after shutting the car off, a fan starts up a few moments later and stays on for 10-30 seconds. I always assumed it was the oil cooler or something, never gave it much thought.

Today, the fan turned on and stayed on for several minutes. It was a beautiful, 70 degree day in California, so not particularly hot. I had thrown a code (P0012) while driving on this trip - that will be it's own thread later on as I sort through that - but I'm curious what this fan actually is? I confirmed it's not the radiator fans - they were not moving. A lot of hot air was blowing out from the front part of the car with the hood popped - is it the heat/air system for the cabin, and if so, why would that come on after the car is turned off? Did some searching but came up empty.

[Finnegan]

Fan turning on happens to me quite frequently even on somewhat cool days given the slight incline and load of the highway near home. I really don’t think it’s abnormal. I’ve noticed this behavior across three different Z4m and one M3. Camshaft code is likely separate.

[Reborn_]

I figured as much, thanks for responding. I do have a very steep hill leading to my house, so that could be the reason. I'm curious what the fan is, do you know? I didn't see the radiator fans spinning, so now I'm curious.

For the code, I've got the Beisan VANOS solenoid en route, hoping that takes care of it.

[Finnegan]

Originally Posted by Reborn_

I figured as much, thanks for responding. I do have a very steep hill leading to my house, so that could be the reason. I'm curious what the fan is, do you know? I didn't see the radiator fans spinning, so now I'm curious.

For the code, I've got the Beisan VANOS solenoid en route, hoping that takes care of it.

Fingers crossed the solenoid does the trick!

Unfortunately I don’t know where that fan is. The idea of a finger “finding” it while looking/listening has made me less curious. 7/10 times if I restart the car momentarily it turns off. Since I put it back on the charger I don’t worry much about it running a bit these days - no error codes and I’m happy!

[Reborn_]

Yea I'm not concerned enough to spend time on trying to find a fan either . I just became pretty curious if anyone out there knows more about it.

Swapped the solenoid yesterday (and did all the Beisan recommended cleaning and o-ring change outs) and reset the ECU. I just took a small trip around town, maybe 10 miles, and it seems to have done the trick - so far so good.

[Finnegan]

Originally Posted by Reborn_

Yea I'm not concerned enough to spend time on trying to find a fan either . I just became pretty curious if anyone out there knows more about it.

Swapped the solenoid yesterday (and did all the Beisan recommended cleaning and o-ring change outs) and reset the ECU. I just took a small trip around town, maybe 10 miles, and it seems to have done the trick - so far so good.

That’s great news! Fingers crossed does the trick going forward.