I was going to make a joke about maybe you had deer whistles on your car. So I went looking for a picture and came across this from a manufacturer who appears to be totally unclear on the basic concept and decided to post it instead...
![Hood Giraffe Giraffidae Automotive tire Grille]()
You don't have any of these on your car, do you?
Seriously, though, it sounds (no pun intended) like an aerodynamic effect, not mechanical. If you're moving fast enough it whistles. Doesn't matter what the motor and gearbox are doing. A bad wheel bearing might whine at first, but it will quickly progress to grinding. That's how you isolate it - you wait for it to make enough noise you can be sure which wheel it is. Helps to isolate noises sometimes if you have someone else drive the car and you sit in the center of the back seat and listen.
You don't have any of these on your car, do you?
Seriously, though, it sounds (no pun intended) like an aerodynamic effect, not mechanical. If you're moving fast enough it whistles. Doesn't matter what the motor and gearbox are doing. A bad wheel bearing might whine at first, but it will quickly progress to grinding. That's how you isolate it - you wait for it to make enough noise you can be sure which wheel it is. Helps to isolate noises sometimes if you have someone else drive the car and you sit in the center of the back seat and listen.
