If I roll down either of my rear windows more than halfway, and drive faster than 45 km/h, I get this horrendous pounding vibration in the entire passenger compartment (at about 15-20Hz, I don’t have an oscilloscope or anything). It goes away if I close the windows or decrease speed below 45 km/h. I went as fast as 90 km/h but the vibration continued.
What could be causing this? I have an idea, but I don’t want to bias your brilliant minds with my mediocre theories. My vehicle is not equipped with a flux capacitor
How do I get rid of it, aside from rolling up the windows or driving slower than 45 km/h?
This review states that “There is an intolerable low frequency vibration with rear windows down, front windows up.”. Sounds similar to what you are talking about.
If so, what is happening is that the wind blowing across the open window(s) is making the air inside the car resonate, exactly the same way as it does when you blow across the mouthpiece of a flute or the neck of a bottle. The only difference is that the frequency at which it resonates is much, much lower, due to the volume of air.
I’ve had this in virtually every 4-door car I’ve ever owned. Both my Explorer and my Le Sabre do this. Very annoying, but I don’t know of anything one can do to change the dynamics.
I have one. Years ago my kids used to beg me to do “rum-pums”. That was their word for the effect. It wasn’t something you’d want to do for a long time but the kids thought it was cool so we’d do it for 10-15 seconds.
I had a 1992 Pontiac Bonneville that did exactly the same thing. I just had to put the windows up to stop it, or put the front windows down. When i bought a 2000 Bonneville, the problem didn’t even exist.
So perhaps just the body style of certain vehicles and their accompanying aerodynamics makes them resonate the way you and i have felt.
