I have a 2010 535i with the same problem. please let me know if you find out what it is.

 

I faced the same issue with my e39, I think it is a loose metal pice/ hose touching steering column! The vibration is increasing with speed and causing this sound.

Hope this help.

 

it's not a mileage issue- it's the sun and the elements taking their toll on the seal. if you always park outside 4-5 years is enough for it to start cracking, unfortunately. You can just pull the old seal off and work the new one in without removing the windshield. It takes time and effort, but better than the risk of wind noise if you reseal the windshield.

That reminds me- have you checked in the sunroof area? is the noise louder with the sun shade pulled back?

 

How did you fix it??? removed the steering wheel?

 

I bet this is it...my '95 525i did it...and my '08 535i does it too. It's the exterior rubber seal around the windshield. The wind at high speed makes it "flap" and it makes that kind of noise.

 

Just inspect steering column area for any metal pice sitting close to it, I think there is power steering hose fixed close to the column.

 

Then it's a manufacturing defect, because cars as new as 2010 and 2008 have that problem it's not a wear/tear thing. These vehicles should be able to withstand the wind when driving at 85 mph.

 

I don't think it's air related. The tone and volume seem to be fixed. If it's air related either the volume or tone would change as you change your speed. Also, it's hard to tell on the video, but it sounds more like a vibration ringing noise than a whistle. I could be wrong, but I'm going for a metal piece vibrating against another piece.

To test the windshield noise theory, why don't you put a bunch of painters or masking tape around the windshield seals and see if you still get the noise?

 

It's the seal around the windshield. You need a new windshield. this is a common problem and has been discussed on m5board.

 

I agree...however...on my '95 525i, it only started to do it after several years. I just added a very small bead of silicon under the exterior windshield seal (only to a 3 or 4 inch portion directly in front of the driver) and it fixed the problem. Also, I don't believe that the tone/pitch of the noise changed with speed...I know it would seem like it would, but I don't think it did.

I took my 535i in for the problem and they said they couldn't duplicate the problem...because it only happens at > 90mph...and they aren't gonna drive the car that fast to try to duplicate it...maybe I need to go to BMW in Germany to get it fixed