It was a hot weekend here in the Bay area, and I rolled down the driver side rear window while stopping at a light. Then, as I picked up the speed toward 50 mph, The air inside the car oscillated so serverely, that I thought my ear drums gonna pop. Does anyone have similar experience? I wonder if it is unique to A4, or other 4 door cars have same problem.

I guess it is a similar problem with the sun roof. ie: If the roof is open, but all windows are shut, and you roll about 50kms (about 30 miles/hour), you get the same effect. If you drive slower or faster, no problem. As in the case with the roof, you probably have to open another window just a crack to adjust for the air pressure difference. It is similar to the effect you get when you blow over an open beer bottle...

Don
2.8 qms pearl

Actually the problem with the sun roof is described in the Audi new-owners video.

Don
2.8 qms pearl

If you are worried about wind in your face, try opening the front left window and the rear left (and the sunroof if you like, leave all other windows closed) the air travels nicely through the car w/o blowing in your face or causing excessive noise.

We have a '97 A6 Wagon, and the air oscillation (or whatever you call it) with the moonroof or only one window open can be unbearable. As others have noted, cracking open another window cures it, but it would be nice it that didn't have to happen. When I picked up my A.4 1.8T I was prepared to experience the same thing, but no....with the moonroof open it is unbelievably quiet, no oscillation at all even at highway speeds. Indeed there's very little air movement within the cabin period, with the moonroof open. Until I read these posts I'd assumed that Audi "got it right" with their A4 cabin. Now it seems that it's a highly variable condition that may or may not occur in any given car within the same model. I never woulda thought that.

Rick

Try driving exactly 50 kms/hr (31 miles). It is something with the aerodynamics of the car. Audi even acknowledges it in their user-manual video.
If you drive slower or faster, no effect. Right now, the only noise that bothers me is the squeek from the bushings.

Don
2.8 qms pearl

Guys, read the post before you post :).
Tksung, I had this very problem on my 95 Jetta GLX, had to open the front window a little.

I don't know if this is typical of modern 4 door cars, but there you have it. It seem to run in the Audi-VW family.

adc

stops. I think that as cars have become more areodynamic the pressure difference oscillates from high to low inside the car causing this effect. Just my opinion. I have seen this in a lumina mini van and the A4.

I asked the same question a couple of weeks ago; the best suggestion was, with just the roof open, to run it closed about two clicks on the rotary dial. It worked!

Jack

I drive with roof open all the time, but I haven't noticed resonance problem with it yet. I wonder if the problem's gone away in 99.5 with larger moonroof opening. Or, maybe I haven't driven in exact speed for the natural harmonics to kick in...

.

as far as i know, this happens with most 4 door cars. just another case of aerodynamics and wind stuff..

Do you have the "air coming in thru widow switch" problem (see above post). You need that option to stop this phenomenon.

just put the damn widows up, close the sun/moon roof, and crank up the A/C! You guys crack me up!!!

I heard rumor that the new symphony radio automatically generates high amplitude 10 Hz sound to cancel out the oscillation when the car reachs the resonant speed with window/moonroof open.

Seriously, I thought the air through window switch gaps was because of the air pressure differential, according to bernoulli's (sic?) effect. I really don't think it was intentional. If they really intended, I'd think they would've used the real ventillation system rather than gaps between window switchs!

nt