MODERN PROBLEMS: That Vibrating ‘Wub Wub Wub’ That Comes From Cracking One Car Window? It’s Not Just You!

The vibration actually has a name. It is the Helmholtz resonance, or “wind throb,” and it has long plagued an auto industry that has generally made cars better with each passing year. It is as likely to assail a pricey sports car as it is a compact sedan.

The most common instance of wind throb is when a back seat driver rolls down a window when the front ones aren’t cracked. The usual advice: Open a front window. There are other scenarios, too.

The throb is caused by wind passing over flat openings, like a window, in a way that matches the “resonance frequency” of most car cabins. The phenomenon is just like what happens when someone blows over the top of a Coke bottle.

“Most vehicles today, regardless of manufacturer, are sealed so well to improve NVH levels, they can’t vent the volume of air needed to reduce or eliminate the phenomenon,” Jason Nunamaker, a Toyota Motor Corp. expert on vehicle frames, said in an email. NVH is an industry term that stands for noise, vibration and harshness.

I’ve found that cracking a back window slightly wider than a front window completely eliminates the throb, but that nothing helps when it is caused by a poorly designed sunroof.