My Prius makes a very strange sound when one rear window is down

<div class='quotetop'>QUOTE(BayouBulldog @ Apr 19 2006, 10:23 AM) [snapback]242045[/snapback]</div>

I have not done this in the Prius, because I don't usually have occasion to drive with the back windows open, but it did happen to me once in my last car - 1988 Nissan Stanza. I had a passenger in the back seat who gets warm easily and he opened the back window about half way in the middle of winter. I started to hear a loud howling noise that sounded like I was driving on a grooved road surface and my ears started to pop. I made him close the window and it stopped.

I just did a quick search and found that someone who tried to sue for the damages caused by noise caused by an open windows in a Land Rover. http://www.lemonlawclaims.com/2002%20Land%...20decisions.htm

 

There have been other threads about this phenomenon. If you think it's weird with one window down a bit, try 'em both down and cruise about 48 MPH. You will feel the vibes all the way through your body as if your whole car were a massive subwoofer.

As soon as you crack open the front windows, it goes away. :huh:

 

The interior of the car is resonating. Not unlike blowing across the top of a bottle. Its pretty specific to the car geometry. My wife's highlander does it when the moonroof is open. I've had other cars do it with the rear windows as well. I believe the ear popping is due to a lowering of air pressure by standing waves in the car. If I remember, I'll take along a barometer next time out and see if I can measure it.

 

ya this has happened on a few cars i have owned. what i do is crack front and back on same side a ½ inch or so. with two windows open you get much better circulation anyway so opening the windows wider is not necessary.

 

There is nothing wrong with the car. It is just aerodynamics at work. I have been in many cars that do it, Olds, Volvo, Honda etc. I suppose it is possible for the manufacturer to prevent the problem by doing special wind tunnel testing or something but the Prius is a Toyota not a Lexus. Just keep adjusting the windows till you find a sweet spot.

 

If I roll my front drivers side window down all the way, all I have to do is just crack open the rear window less then an inch and it goes away.

I've had few cars in the past that have had this same phenomenon. Technically, I'm not quite sue it is properly described as resonance.

Peace,
Cosmo

 

This is harmonics set up by opening the window. You can compare it to the noise made when blowing across the top of a soft drink bottle. Opening another window changes the physical characteristics, and thus the equilibrium conditions making the low level harmonics favorable. This also happens in other cars as well, like my old VW Jetta.

 

<div class='quotetop'>QUOTE(K5VMI @ Apr 19 2006, 06:31 AM) [snapback]242114[/snapback]</div>

My '97 Jetta, too.

 

<div class='quotetop'>QUOTE(etyler88 @ Apr 19 2006, 11:37 AM) [snapback]242081[/snapback]</div>

The Prius is designed to have very low aerodynamic drag. The airflow over the body and windows is as smooth as they can make it, so when you open a window it induces turbulence which produces noise and pressure waves. It is possible to minimize these effects when designing an automobile, but gernerally at the cost of increased drag.

Modern automobiles, such as the Prius, are designed to be driven with the windows up, using the ventilation system and A/C to control cabin temperature.

Tom

 

<div class='quotetop'>QUOTE(BayouBulldog @ Apr 19 2006, 07:23 AM) [snapback]242045[/snapback]</div>

My '06 Prius does it...as did my old '01 Honda Accord, and my older Civics. It isnt a problem with the car, it is simply an effect of the wind. It feels kind of like being inside a real big pipe organ pipe when it is played. Just open another window a little bit.

 

Mine does it and it can be very uncomfortable. I thought it was just a wind thing.

 

I don't think it a Prius thing. I have it happening and thats in my Small SUV.

 

Someone called this effect helicoptering. It's very unpleasant, indeed.

 

It happens in certain situations usually related to the environment I'm currently driving in. I have my driver window rolled down more than 50% of the time, and it can happen at varying speeds. Wind direction seems to play a big part. I just roll down rear driver window a bit and it shuts of the 'copter. I probably don't copter frequently since I usually rest my arm on the sill.

 

I about wet my pants the first time it happened. Thought it was Armageddon. Quickly slowed down and pulled over.

Now that it's happened a few times (sometimes I induce it when I'm bored) I've noticed that the "pulsations" can have very different patterns, in terms of fastness/slowness.

Some day it may fool me and suck my brain out one ear.

 

Yup, happens here too.... combination of aerodynamics/wind/atmosphere/circulation, etc. Spend some time in various convertibles, or better yet, ride a motorcycle, and you'll experience a different world where winds/air masses have a direct impact on you.... Sort of a foreign feeling for most of us who are used to riding IN vehicles...

 

Yes I have noticed it in every car I have owned. I don't like "dead" air, so I usually will roll down the back window to get some ventalation w/o the noise of the front window being down, just have to be careful not to roll it down too far or you get that noise.