Strange noise in 4wd
 

Hello ! My car is C-Crosser 2.2, automatic, 2010. I have a very strange problem that when my car is cold in 4wd it makes a noise mostly when turning but when I put it in 2wd the noise goes away. When the car is warm (for example if I drive it for couple of kms) in 4wd the noise disappears. The car still drives really well but the noise is irritating it sounds like a whirring rattle.

Any ideas what to look for ?