It's weird it starts right around 47ish becomes loudest at what I'm calling 52mph and then starts to die down and is gone by by 57-58mph.

I'm just going to call the dealer. It's under warranty no point in screwing around with it myself if I don't have to... I've got a 7 that will soon be out warranty for that.:bustingup:(

Hi - I've been having a constant pitched noise when driving from 20 - 70 ish... The noise/tone would not change over different surfaces, just get louder etc.

I had upgraded to 214 rims and Conti DWS tires, after the upgrade I noticed the noise a lot more than with my 19 inch rims. I did notice it very faintly on the 19's which is why I started looking around at other possibilities, other than tire noise. Also, I got Vredestiens, had the noise, switched them to Conti DWS because my tire guy said it was the tread pattern... both tires made the noise.

After poking around, everyone has said both of my tire choices should be very quite (for the size), so I took it to the dealer, and they said it was tire noise, but later found a bolt was loose on the differential. They said they tightened and fixed the problem... But, the noise was still very much there. So I rotated the tires, checked for bad bearings and came up with nothing on my own.

I took it back to the dealer, and they finally diagnosed it as a bad rear differential. The part is on B/O for two weeks, so I will keep you posted after it is replaced.

My car is a 2010 x5 35d with 2,000 miles on it! So it could be your Diff as well...

Yeah, I've got to call and make an appointment for it. It hasn't gotten anymore pronounced and doesn't affect drivability or anything it's just annoying. I definitely think it's a gear in one of the diffs. I had a rear diff go bad in my 335 and it would make a similar noise but, only on decel.

Good luck with yours.