BMW X5 E70 noise

[fiE70]

I faced a weird noise issue with my BMW X5 E70 40d from year 2011 which for I would really need your guidance. The car is driven 150 000km.



The issue is the whistling/howling noise while driving 40-110 km/h and while NOT applying gas. When the gas pedal is pressed even a slightly the noise disappears and vice versa.

The phenomena doesn't appear right away while you start your car from cold and proceed to motorway. Typically it requires >30km driving so the car would be warm. Some time to time the noise also disappears.



The noise seems to be coming to the cabin from the rear side of the car.

The front drive shaft from transfer box to front differentials has been checked in campaign and no issues were found.



What could be causing this issue in E70? Does the support bearing for the rear drive shaft cause this kind of issues?



Next step plan is to change the oil to rear differential and to transfer case.
Thanks!