Strange whistle/whirring noise on highway 45-65mph

[Big_Cuss]

While driving today I noticed a weird steady whistle/whir/hum combo noise that only shows up for 5-10 seconds at a time, that comes and goes every few minutes. It was a solid pitch, so not changing with rpm, load, etc. Wondering wtf it could be?

This is in a 2018 TRD Off Road with stock KDSS suspension.

When I first heard it a few weeks ago, I thought it was those inner fender plastic aprons catching crosswinds, but more recently I've heard the noise even without strong crosswinds.

Anyone else have this or know the cause?

 

[Big_Cuss]

Update: The noise only starts to happen occasionally at 50-65mph. Like a light steady whistling or whirring -- and it stops the second I touch the brake pedal.

Bad wheel bearing? Brake disc touching the pad slightly somehow?

 

[Bilbo]

Vortex generators?

https://youtu.be/6qcxnn8KWCo

 

[Big_Cuss]

I thought maybe that... but would touching the brakes stop it?

 

[Toffees]

Update: The noise only starts to happen occasionally at 50-65mph. Like a light steady whistling or whirring -- and it stops the second I touch the brake pedal.

Bad wheel bearing? Brake disc touching the pad slightly somehow?

I get something similar but at higher speed, a high pitched noise. Sounds like brake noise, but I don't get it at low speeds/when braking. It's intermittent, or else I keep my radio up too loud most of the time. Interested in seeing what you find out.

 

[Swipter]

Vortex generators?

https://youtu.be/6qcxnn8KWCo

The things I learn on this forum.

 

[Grape Ape]

Possibility is that it's your aero bumps on the side mirror, this happens to me once in a while with the right conditions of speed and natural wind. Constant high pitched sound until I break or turn a different direction into/out of the wind etc

 

[Big_Cuss]

Possibility is that it's your aero bumps on the side mirror, this happens to me once in a while with the right conditions of speed and natural wind. Constant high pitched sound until I break or turn a different direction into/out of the wind etc

That's exactly the issue I have. So weird. I wouldn't think braking would change it.. but then again, it would change the pitch, airflow just a tad.

 

[Toffees]

Vortex generators?

https://youtu.be/6qcxnn8KWCo

Oh, wow, of course I've seen these and know what vortex generators are, but didn't put 2 and 2 together to make 3. That's almost certainly it.

Interesting that Toyota does this for stability (although they note that it improves fuel economy as well).