My brother has a BMW X5 2003. Recently he noticed that when you accelerate , there is this wining noise coming from the front of the car. He than thought that the car needs a service and after the service the wining noise is still there.
This only happens when you are accelerating and stops when you have reached the required speed. The car acceleration is fine (as it should be).
The noise seems to be coming from the front wheels.
Does anybody have any idea what is causing this?
Any suggestion will be appreciated.