[supernova1]

My 2013 X3 XDrive28i starts presenting whistle/whine noise at around 35-40 mph. It is a faint noise, very similar to turbo whine when it slows down after engine is off. It does bother me though.

I experimented with car to get an idea about the noise source. It is definitely not engine-related, as its pitch does not depend on engine RPM, but depends on the car speed.

As my car is still under CPO, I brought it to dealer, and drove with a mechanic. He did acknowledged presence of noise, but offered no reassurance that they would get to the bottom of it as it "sounds like a normal noise of an aging car". Really???

I looked around forums, and the closest to this noise was central support bearing noise (it sits on the main driveshaft, holding it in the middle).

Did anybody have a similar noise, and what was the source of it?

[Scout10]

Yeah . . . wonder if the Mech would furnish his source for
old car noise Vs. new car noise?

change all window positions when noise is highest?
have some one open . . . doors on the move?
Fold in side mirrors ......
Move wiper blades
How long has this been going on?
Have you changed anything on it?

saw a mech use wide blue painters tape to alter air flow
to detect wind noises

[Iowa X3]

It could be a wheel bearing going out. My 2013 28i had the left rear wheel bearing start making noise at around 30,000 miles last year and I got it replaced under the manufacturer's warranty right before it expired.

Take the car out on a long straight stretch of road and try slowly swerving back and forth at different speeds with all of your windows closed and the radio off and see if you can tell whether the noise changes while doing those slow swerves. The swerves take weight off and put weight on different wheels and can sometimes help find where the sound is coming from.

[dreamspeed]

Yup, check the wheel bearings. I had a whining sound coming from the rear that sounded like it could be "normal" but was still a bit off to me.

I drove it on the highway and shifted through the gears to determine if it was tranny related. It wasn't. Rolled down the windows and drove over rumble strips to see if it was tire or aero related. It wasn't. Revved the car while parked and didn't hear any noise. Figured it was probably wheel bearings.

Took it to the dealer and they were able to pinpoint the problem by putting it on a lift and inspecting each wheel and spinning the wheels by "driving" it in the air

[supernova1]

All good suggestions, thanks everybody!

[bryguy86]

Interestingly enough, I have the same issue on my G01. It happens only at exactly 37mph. Techs thought it was coming from the back of the car and replaced the entire rear end (diff and axles). Called me and told me the issue was isolated and fixed after having the car for 3 weeks. Went to pick up my car, drove 500 feet, exact same noise at the exact same speed. Car is going BACK in to the dealer in two days.

[thetyrant]

My 2011 f25 30d does a whine noise at 35-40mph as well but only when ambient temps are below around 12c, above that and after car is fully warmed up no noise unless a very cold sub zero day then it can remain!

It sounds like its coming from middle or rear of car hard to pinpoint inside the car!

Ive tried all sorts during last and this winter (see below) but never sorted it, then spring/summer came so no noise and forgot about it for next 10k miles or so car ran perfect.

This winter it started again and tried a few more things with no difference, as spring is on the way it will probably be forgotten again!

Ive done below over past year...

Replaced all 4 tyres with new matching Falkens.

Replaced all drivetrain fluids (gbox, tbox, diffs front and rear) no nasty stuff in oils either.

Replaced Front propshaft with new ( UJ was partially siezed causing different noise)

Replaced centre bearing on rear propshaft

It sounds like a wheel bearing type noise but swerving the car around makes no difference so dont think its that and no play i can detect, not easy to get a proper feel without disassembling hub though.

Had me baffled since i got car!, i really need to find a friendly local garage close by that will let me run it up on a 2post when still cold and making noise with undershields etc off see if we can pinpoint it at all but not managed yet.

Any ideas welcome