E39 530i MSport High-Pitch Sound Above 80kmh

[azan23uk]

Hi All,Driving at speed above 80kmh, I can hear a faint and continuous high-pitch sound coming from the front of the car and gets louder especially above 120kmh. I put the gear to "N" while doing 120kmh and let the rev down to almost idle, but the sound is still there. Switched off the A/C and stereo, the sound still there. So I can conclude that this high-pitch sound is not rev-related or due to A/C system. It is speed related and doesn't sound like wind whistling. Changed the front bearings even and swap the tires to the back but the sound is still there. It's irritating and spoils the quiet and serene ride our E39s are famous for. I never had this problem with my old 528i. Anyone has ever experienced this problem? TQ