Very Loud Fan - Need info please!
 

Hello everyone. Great forum!
I have a used 2006 530xi with 60K miles.
The car was bought used and I'm still learning about it.
I am very happy with the way it runs, and haven't had any problems with it so far.

One thing I notice though, is that if i don't let the car sit for a while to "warm up" the fan goes on (loud) when i start driving. the car is not overheating when this happens. It is actually more common when it is cold.
If I turn on the heat or AC the fan turns off. It doesn't do it if the car has reached optimal speed.

Any of you have experience with this? Is this normal on these cars? anything i should look out for? what could it be?
I've owned other BMW's before this one, an e46, and a e53 x5, but haven't seen this until this e60.

I appreciate your input. Thanks!

anyone?!