odd issue

[Dekion]

Ok, this issue is odd and it may not even be an issue.

Usually when I roll the front window down, too much air is hitting my face. So I roll one of the back windows down and somehow the wind from the front stops hitting me in the face.

The other day, I had my front window open and a rear one open. I closed the front one first but left the rear window open. All of a sudden, my car started shaking soooo bad. And it was killing my ears with all the pressure. The back panel (where the speakers sit above the trunk) started vibrating up and down so hard that my ear drums felt like they were going to pop. And the WHOLE car started shaking while i was driving.

Is this normal? Or has anyone ever done this in their 4 door BMW? With one back window open the whole car shakes and your rear panel jumps up and down big time??

Thanks.

 

[brahtw8]

I have experienced vibration, a/k/a wind buffetting with both DS windows rolled down, but relatively minor.

I have never experienced the in-car sonic distortion you describe. I would expect it was a freak occurrence. Have you tried to duplicate it?

 

[mallards]

i know what you are talking about ... this is fun ... =)

roll up all the windows and go 45 mph ... then hold down the wind deflector on the sun roof (a black piece of plastic towards the front)

the wind along with the cars design makes a terrible bass-like noise

besides doing that with the conditions setup for the car to make the noise ... ive never had it happen

Ben

 

[MrElussive]

If it is good weather and you are the open-weather type, then you should open both front windows. If you wanna do highway-cruising, then you should open all four windows as this will pressurize the cabin better and you will hear less wind rushing in and out of the cabin (you can have the sunroof open, too as long as you open both front windows and both rear windows).

 

[steve330xi]

Dekion - when I had a '95 318i I had that exact problem. With only one back window open when I hit a certain speed the vibration was unbearable. Like the old Henny Youngman joke; "I said Doctor, it hurts when I do this. He replied, ok, don't do that". So I didn't do that. Now I don't have that problem with my '03 330xi.

 

[bmwrocks]

The phenomenon you describe happens in my X5, although I cannot say it happens with the severity you described.

I just don't let it happen anymore, that's my solution.

 

[PuShAkOv]

You sure it wasn;t just window vibrating from the wind? When only one window is semi open it takes a harder hit.

 

[Dekion]

push

pushakov, no, it's not the window at all. hehe. i'm not that bad at seeing issues.

yah, it's a terrible bass like noise and it kills my ears. due to the massive vibration. it actually feels like it's moving the car. the bass sound is like knocking my ear drums in. i can't explain it any other way.

i'm glad other folks know what i'm talking about.
i just don't like not being able to open a back window by itself.

 

[Kirby]

My '95 Suburban ("The Bus") does the same thing, and I have talked to other Suburban owners who have noticed it. It seems like it's an oscillation of the air pressure in the cabin. Something like the air gets pulled out of the cabin until the air pressure drops too low, and then air rushes back in, then gets sucked back out, etc.etc.

I also think it might be a result of the extensive Computer Simulation & Wind Tunnel testing during car design. The bodies these days are very aerodynamically tuned, and they do that with the windows up. The windows down really does screw up the aerodynamics, and this is the result.....

 

[PuShAkOv]

Since its a new car... take it to the dealer for a warrenty fix. Let them drive the car and see. I wounder if the car is going to fall apart if you reach 128MPH.

Personally, I do not think the problem is related to windows... just doesn't make much sense... my guess it is something with the exhaust system since when you go faster the pressure on the pipes is higher ...

 

[Dekion]

thanks

Thanks for your input Push. However, perhaps you misunderstand. It's definitely not the window vibrating or anything outside of the car. It only happens when I let air in the car via the back window only. There is sooo much pressure build up inside the car that your ear drums feel like they're going to explode. Almost like you have so much BASS coming from the back seat and it's pounding you. Definitely not the exhaust. That sounds great.

As some of the other nice folks suggested, I just won't be able to roll down a back window by itself. I'll have to have a front window open at the same time. This issue is only with the 4 door cars.

Hopefully that explains it to ya a little better.

From the sounds of it, other folks have the same issue so I'm not as concerned.

 

[Bryan330i]

I do not have any idea but I think that it would freak me out.

 

[bmwrocks]

It has nothing to do with exhaust or the windows themselves. It is a low frequency "beating" sound that occurs if a back window is opened by itself. It's freakish. Has something to do with air circulation in the vehicle.

It can't be a warranty item as it is not a defect in workmanship.

I think BMW would consider it "as designed".

 

[BEEMIN]

I agree. This is a not-so-wonderful BMW phenomenon that I have experienced with every single one of my BMWs. It's due to the design of the car mixed with the size of the windows, yadda yadda yadda. I'm not an engineer so I won't even attempt to try and explain the dynamics of this but I will agree that it's annoying. I've experienced it at 90 mph and have even subjected my two big dogs to it when I put them in the backseat, rolled the windows down (I forgot) and it made them howl. You can imagine how painful that must have been to their sensitive ears.

Really wish someone could figure out a fix.

 

[Dekion]

Thanks guys

I appreciate that you guys were able to understand what I was trying to explain. It was hard to explain but you guys knew what I was talking about. It makes me feel better because it's not just me.

Bryan, next time your on the road. Just open one rear window while driving while all the other windows are closed. It happens to me around 55mph.

 

[Kirby]

If anyone wants to find out what it sounds/feels like try this:
1. Close your palms into a cup shape.
2. Slap your left palm to your left ear fairly hard.
3. Now do the same on the right ear.
4. Repeat (alternating left then right) as fast as you can until you go deaf or crazy!

That's close to what it sounds like. It WILL drive you nuts.