[Jimpetut]

Just had a really strange episode. I put down back window and car started making a really loud noise. Sounded like a flat tire times 10.Front window down nothing.Only rear window down and above 30 miles per hour.My ears actually started ringing it was so loud.Has anyone else had this happen with your Trailblazer?

 

[ZR2LIFE]

I've had this happen in several cars and it's very common with many makes and models. When you have the front windows up and the rears down you create a harmonic resonance which sounds like a low thumping bass sound. The only solution is to partially lower at least 1 front window.

 

[Jimpetut]

I've had this happen in several cars and it's very common with many makes and models. When you have the front windows up and the rears down you create a harmonic resonance which sounds like a low thumping bass sound. The only solution is to partially lower at least 1 front window.

Steve,this is really loud.Gonna have my mechanic go for a ride before I call dealer.The noise made my ears ring

 

[Trail Blazed]

I believe this is a pretty common issue with newer cars. My Equinox did the same thing. Cars are built so much tighter.

 

[Saust]

Just had a really strange episode. I put down back window and car started making a really loud noise. Sounded like a flat tire times 10.Front window down nothing.Only rear window down and above 30 miles per hour.My ears actually started ringing it was so loud.Has anyone else had this happen with your Trailblazer?

yes I found this forum because I just had the same issue and almost took it to a dealer. Still considering it. I hope it’s covered under warranty. I am still reading the forum for related stories.

 

[Saust]

Steve,this is really loud.Gonna have my mechanic go for a ride before I call dealer.The noise made my ears ring

What was the results of your mechanics looking at it, did you end up taking it to the dealer? I am relieved to see others are having the same issue but concerned for all of us.

 

[ZR2LIFE]

Steve,this is really loud.Gonna have my mechanic go for a ride before I call dealer.The noise made my ears ring

I believe you and it makes my ears hurt too. It also gets worse the faster you go, but it's not uncommon. It has something to do with rapid pressure fluctuations. If you can easily recreate the sound, see if it slowly goes away when you start rolling down a front window. If the noise persists then I'd definitely get it looked at as it might be mechanical. This resonance only seems to happen in vehicles with 4 doors and only when the back windows are down with the fronts up.

 

[Jimpetut]

What was the results of your mechanics looking at it, did you end up taking it to the dealer? I am relieved to see others are having the same issue but concerned for all of us.

I haven't talked to him yet.i did so e research and this scientific term is HEMHOLTZ RESONANCE.It is fairly common from what I am seeing.

 

[Jimpetut]

I believe you and it makes my ears hurt too. It also gets worse the faster you go, but it's not uncommon. It has something to do with rapid pressure fluctuations. If you can easily recreate the sound, see if it slowly goes away when you start rolling down a front window. If the noise persists then I'd definitely get it looked at as it might be mechanical. This resonance only seems to happen in vehicles with 4 doors and only when the back windows are down with the fronts up.

It starts at 30 mph and does get louder.I had a fly in vehicle and tried to get him out.

 

[Saust]

I haven't talked to him yet.i did so e research and this scientific term is HEMHOLTZ RESONANCE.It is fairly common from what I am seeing.

Mine didn’t hurt my ears and it only starts at around 45-50mph the faster I go the worse it gets . It also is worse on lesser smooth pavements. It sounds like a thumping machine gun / both backs tires are flat or riding over interstate shoulder rumble strips. Doesn’t matter which back window is down I hear it from that window (so when left is down it sounds like a left back flat, when right is down it sounds like back right is flat, and both = 2 flats. I haven’t tried the rolling front window down to see if it stops trick, I’ll do that tomorrow.

 

[Walkinshaw Val]

It's God awful I agree.
However totally normal.
It's called Buffeting based on Helmholtz resonance principle/explanation.
Crack your front window two inches and it'll go away.

 

[Shogunmark]

i have had this buffeting noise in almost all of my vehicles over the last 15 years.. its common and you just have to equalize the pressure by lowering a front window just a little bit.