Strange Vibration?
 

As my wife and I were driving our new X5 home we opened the sunroof, turned-up the radio and were loving it! After about five minutes we looked at each other and were getting a vibration feel, started to get a headache, and had to pop our ears? When we rolled down one of the other windows the effect went away. I spoke to a someone who has an X5 and they said that too happens in theirs - because the car is built so tight. Does this make sense? Thanks a lot.

Well, yes. But not really because the vehicle is "built so tight," it happens to most vehicles with large sunroofs and a large open area inside the vehicle, e.g., SUVs.

What is happening is a buffeting as the air flows over the open sunroof, when it hits a resonate frequency of the vehicle's air volume, sort of like the sound you get when blowing across the top of a bottle. Cracking a window changes that resonate frequency and the effect goes away.

Some vehicles do it worse than others, and some have a perforated or other oddly-shaped bit that pops-up at the front of the sunroof when opened to reduce the effect.

The X5 and X3 seem to be more prone to this effect, perhaps because the sunroof is so large.

It happens with every vehicle, just with different intensity. The larger the sunroof, the louder and more intense the reverb.

i get the same thing in my crew cab with the rear windows down.

My e36 325i does the same thing if the rear windows are down about halfway or more and the fronts are completely closed.

Yes my X5 does it at 50mph with the panoramic sunroof full open, closing it a little stops it, or opening another window a little as mentioned. Driving faster also stops it :zoom:

Do those wind deflectors (sold as accessory) resolve this problem?

No they don't but they are great for opening your windows slightly in the rain.

Just crack your windows and you won't get that dizzying noise

Thanks for all of the responses. Overall....This machine rocks!

Exactly. I've always gotten quite annoyed when only one window is open in any of my cars, although I have to say I haven't ever noticed a problem with the sunroof. :confused: