We've just noticed an issue with our 2012 Mini Countryman S All4. We get a surprisingly loud, low frequency, pulsating noise when we roll down the rear door windows at highway speeds. It's not just annoying. It's loud enough to be physically uncomfortable.

The noise happens when traveling over 60 mph with just the rear widows down. The noise stops when we roll down the front windows. We don't get the noise at all when the front windows are down regardless of what we've done with the rear widows. We do not have a sunroof. I'm guessing the noise comes from some sort of wind resonance.

Has anyone else had this problem? Any ideas on how to correct it? I'm going to call the dealer on Monday and see what they have to say.

Thanks!

 

Many modern cars do this....heck my wifes highlander does, and most any rental car i have had in the past 5 years does this....modern aerodynamics....

 

Its just wind buffeting...every vehicle I've driven does it at some combination of windows up/down.

 

Dont roll the back windows down. Problem solved.


: P

 

+1

Every car we have owned recently, does this. We use the a/c, or roll the front windows down. Or, in the case of the Jeep, take the doors off entirely! Talk about *noisy*!

 

My soon-to-be-traded Passat and my wife's Highlander both do it if a single window is open. My preferred way to mitigate it is to tilt the sunroof.

 

sun roof cracked or open + rears down is fine.

 

I really wish more wagons had the ability for the back window to roll down

 

I'm surprised any do. It provides more air flow, but also sucks a lot of dirt and exhaust gases into the car.

 

Our X5 does something similar if you open the panoramic sunroof all the way, but if you open a window, even slightly, it won't happen.

 

indie, +1 on everybody elses observations. It is something to do with outside air flow and pressurization, my Saturn SL2 sedan did it, my Pontiac GP sedan does it now and even the Clubman will to a degree between pass window/sunroof closed. Opening another window or the sunroof allows the pressure fluctuations to dissipate, "noise be gone". Nothing to sweat.
What I would really really like to see for the next gen Clubbie (if they dont kill it) is a drivers side suicide door coupled with rear "mini windows" (the door windows, pardon the pun) on both sides that either roll down or pop open rearward. That would be a great improvement.

 

Amen! In my first Mini ('64), I could just reach waaaay back behind either shoulder while driving, release the latch and push out.
Great extractor ventilation and great exhaust sound, too!
I am surprised MINI did only one suicide door since they have both left- and right-hand drive markets. Maybe chassis stiffness made two doors one too many!

 

The noise you hear is a Helmhotlz Resonance.

It's the same effect you get when you blow across a beer bottle and it goes WOOOO. The cabin becomes a fixed volume and the air passing across the open window sets up a standing wave inside the vehicle at the resonant frequency determined by the volume of the cabin. Essentially the air is a big spring oscillating inside the space.

Unfortunately there's no way to avoid it as long as the speed of the air is contributing to that resonance. You could:

a) change speeds (note that it may resonate at multiples of the same frequency)
b) change the cabin volume (more stuff in the car? buy a new car?)
c) change the way the air enters and exits or eliminate the "closed" volume by opening more windows.

I've found that at freeway speeds, having ALL the windows and roof open fully doesn't have this problem.

 

DING DING DING! ^^^ We have a winner! Nice post, thanks.

Print out y8s explanation above and take it to the dealer. Ask them if they will cover the Helmhotlz Resonance problem on your car under warranty.

Sorry, I couldnt resist.

I kid...I kid