Strange Vibration/Wind Noise

[Saker]

Quoted these from the 4th Gen side....experiencing same

If I am driving at highway speeds and open 1 or both of the rear windows, but leave both front windows closed, I get a very loud vibration or wind noise. If I open one of the front windows an inch or so, it goes away. It almost seems like pressure is building up in the car.

Has anyone ever experienced this?

Can some of you try and see if this happens in your 4runner as well?

Any suggested solutions? I used to have a blazer which I drove all the time with the back windows open with no problems.

The phenomenon is called a "resonant cavity."

Try blowing into a glass beer bottle...Hear the boat-horn noise?

Now try something with a larger opening, say a mayonaise jar. You won't get that boat horn sound.

Same thing's happening in your 4Runner. Lowering the front window a bit is disturbing the walls of the "cavity" enough to prevent resonance. (Actually, lowering the window only changes the resonant frequency of the cavity--drive at some other speed or direction to the wind and you may be able to get it to resonate again, but the pitch of the sound will be different...)

--Dan

A few of the cars I've owned had that same quirk. I haven't had the 4runner do it, but notice that if only the front side windows are down, the wind noise is very loud. I have to open a rear window to change the level of noise.
On a different note, my rear seat belts oscillate at highway speeds. Even when I lock them into the buckles!! I'm thinking of putting pads on then to make them heavier. I don't know if it will get better or worse, but have to do something now that nice weather is here and driving with the windows down is more common.

man i hate that. the 3rd gen moonroof fully open and no other windows open would get a bad case of that, ended up only opening it 3/4 way. i think the new runners also do it, but not as bad as the older gens did.

well at least for me.

I too have experienced this in my 2014.
Over 45 MPH with only the rear windows down it creates something similar to a low pressue area inside the T4R, vibrates the unocupied passenger seat until I either open the front windows or open the sunroof.
Wierd to say the least, first vehicle I ever experienced this in!.

BTW, it won't cause me to get rid of my T4R!

Anyone else experience this???

 

[4FL]

It seems about all four door SUVs do this; my 2004 Explorer did this, my Xterra did this, a friend's Trailblazer did this, even my Hyundai Elantra did this; I think it is a phenomenon common to most cars that can have back side windows roll down.

 

[harper7]

Wind buffeting..Pure physics.Does it in every SUV I've owned including 2 Exploders ,a Denali ,my 4th and 5th Gen with the 4th gen the worst and would feel like your ears were going to blow out. Just open the tailgate window a bit and it goes away.Been discussed on here before.

"The technical term for this effect is the Helmholtz resonance, though car people call it "side window buffeting". Back in the 1850s, a scientist named Hermann von Helmholtz showed that the sound's pitch depends on the size of your container of air and of the opening. The bigger the container of air, the lower the pitch. The smaller the opening, the higher the pitch. If you blow over a bottle, you get a medium-pitch whistle. Since a car's a big container of air, you get a low throbbing noise."

 

[mace.]

I've never had a vehicle that didn't do this.

 

[Saker]

Thanks for the input guys....I never had a vehicle that did this, but that doesn't mean a thing!
Never to old to receive data!

 

[Jeremy556]

I've never had a vehicle that didn't do this.

Me either. Many different makes and models of SUVs, trucks, and sedans, all of them have done this.