Strange vibration

florinus · 01-11-2006, 10:09 PM

So I was speeding along an open road with all windows down and moonroof open. I start to close the windows, front first then moonroof. All of a sudden the car starts vibrating...Im thinking wtf do I have a flat tire? I check the instrument panel, nothing. Apparently the car doesnt like the rear windows being open at speeds around 65mph. Can anyone check this on their car? As soon as I "rolled" up the rear windows it went away. I did get tint for what it's worth.

Hmmm

Dgunsuh · 01-11-2006, 10:57 PM

I haven't checked it with my car, but it did that in my Acura, it's the direction of the wind coming into your car and not having anywhere to flow and it hits the back windshield and re-circulates into the cabin of the car. It's physics where teh pressure of the wind coming in has no where to flow and hit's a "wall" (back windshield).

siriusinvestor · 01-11-2006, 11:07 PM

Hmmmm pretty odd that the vibrations start like that. I would bring my vehicle to the service center ASAP.

florinus · 01-12-2006, 01:07 AM

Thanks, I did some research on it and you are correct. It has to do with unequal pressure and is infact very common. Man it did scare the crap out of me! Felt like a helicopter was flying right over me.

visor · 01-12-2006, 01:49 AM

Yes, Dgunsuh is correct, it has to do with the wind/air hitting a resonant frequency when you only have the sunroof partially open say 2-4 inches and all the windows closed while travelling fast on a highway. I would say it's around 6-10 Hz and sounds like a helicopter right over you as you said.

To remedy this problem, just open either of your rear windows a crack, say 1-2 inches and the flapping sound will go away.

Broken1 · 01-12-2006, 05:44 AM

This used to happen to me in my old car aswell. It was a hatch back and if I opened the sunroof without opening any of the rear or front windows it would make lots of vibration sounds.

I don't open the rear windows in my E90 so I've never experienced this...

David328M-Sport · 01-12-2006, 05:50 AM

yep, open a rear window and it happens almost all the time. had it in my old e36, 46 and still the same in my e90.

i just keep the rear windows closed most of the time.

no drama.

davinet78 · 01-12-2006, 06:05 AM

when i go at high speeds im always with the windows closed

LEDZEP · 01-12-2006, 06:52 AM

This is common in any car with a sunroof. The air is trying to enter the car and aspirate at the same time and the pressure goes berzerk. Putting the rear windows down about 1" each generally takes care of the problem.

325 Baller · 01-12-2006, 07:12 AM

ya i hate that noise. before i got my car and my fat friend beat me up for shotgun (not literally) i would sit in the backseat of my other friends car and that noise is killer. it hurts sooo bad, i wanted to kill myself. lol

jcoo085 · 01-12-2006, 07:27 AM

Yup. Sounds like buffeting caused by pressure differences. My previous cars had this problem when only 1 window was open and it was more pronounced when it was a rear window.

I've had the sunroof open on the autobahn at about 140-150km/h and it has been pretty quiet compared to other sunroof equipped cars.

eleven24 · 01-12-2006, 07:37 AM

That's happened in every car I've ever been in. It's the same effect as blowing across the top of the bottle & getting a whistling sound.

espo · 01-12-2006, 09:05 AM

Try this one... Open the sun roof and fold down the rear seats... Talk about revirberation (sp?). This first time this happend in my old 325 I thought the car was going to blow up or something.

ward · 01-12-2006, 09:23 AM

I don't think resonance should happen in a
BMW

demand a new car!!

01-11-2006, 10:09 PM	#1
florinus New Member 0 Rep 17 Posts Drives: 325i Join Date: Sep 2005 Location: florida iTrader: (0)	Strange vibration So I was speeding along an open road with all windows down and moonroof open. I start to close the windows, front first then moonroof. All of a sudden the car starts vibrating...Im thinking wtf do I have a flat tire? I check the instrument panel, nothing. Apparently the car doesnt like the rear windows being open at speeds around 65mph. Can anyone check this on their car? As soon as I "rolled" up the rear windows it went away. I did get tint for what it's worth. Hmmm
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01-11-2006, 10:57 PM	#2
Dgunsuh Private 0 Rep 72 Posts Drives: 330i Join Date: Dec 2005 Location: NoVA iTrader: (0)	I haven't checked it with my car, but it did that in my Acura, it's the direction of the wind coming into your car and not having anywhere to flow and it hits the back windshield and re-circulates into the cabin of the car. It's physics where teh pressure of the wind coming in has no where to flow and hit's a "wall" (back windshield).
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01-11-2006, 11:07 PM	#3
siriusinvestor Captain 67 Rep 873 Posts Drives: 1989 Ugo Join Date: Apr 2005 Location: US iTrader: (2)	Hmmmm pretty odd that the vibrations start like that. I would bring my vehicle to the service center ASAP.
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01-12-2006, 01:07 AM	#4
florinus New Member 0 Rep 17 Posts Drives: 325i Join Date: Sep 2005 Location: florida iTrader: (0)	Thanks, I did some research on it and you are correct. It has to do with unequal pressure and is infact very common. Man it did scare the crap out of me! Felt like a helicopter was flying right over me.
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01-12-2006, 01:49 AM	#5
visor BMW, can I have some LSD please? 88 Rep 1,591 Posts Drives: 2017 F30 340i xDrive Join Date: Jun 2005 Location: Vancouver, Canada iTrader: (0)	Yes, Dgunsuh is correct, it has to do with the wind/air hitting a resonant frequency when you only have the sunroof partially open say 2-4 inches and all the windows closed while travelling fast on a highway. I would say it's around 6-10 Hz and sounds like a helicopter right over you as you said. To remedy this problem, just open either of your rear windows a crack, say 1-2 inches and the flapping sound will go away. __________________ 2006 330i \| TiAg \| Black \| Al \| 6MT \| Sports Package \| Logic 7 retired 2008 335i \| AW \| Black \| Al \| 6MT \| Sports Package \| Logic 7 retired 2013 328xi \| Red \| Gray \| Al \| 8AT \| Sports Line \| Premium \| Executive \| Heat Pkg retired 2017 340i xDrive \| Estoril \| Black \| Al \| 8AT \| M Package
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01-12-2006, 05:44 AM	#6
Broken1 Addict 203 Rep 2,074 Posts Drives: 2024 X5 40i M-Sport Join Date: May 2005 Location: Ontario iTrader: (0)	This used to happen to me in my old car aswell. It was a hatch back and if I opened the sunroof without opening any of the rear or front windows it would make lots of vibration sounds. I don't open the rear windows in my E90 so I've never experienced this...
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01-12-2006, 05:50 AM	#7
David328M-Sport Brigadier General 101 Rep 3,566 Posts Drives: F30 M-Sport 328i Estoril Blue Join Date: Jun 2005 Location: Melbourne Australia iTrader: (0)	yep, open a rear window and it happens almost all the time. had it in my old e36, 46 and still the same in my e90. i just keep the rear windows closed most of the time. no drama. __________________ 328i M-Sport, Estoril Blue, Carbon XP 35 Tint, front heated seats, black Dakota, Sports Suspension, Anthracite Headliner, HUD, Pro Nav, Sunroof, hk 600w, Bi-Xenon, 19" 403M wheels, Reversing Camera, DAB+, Xenon, BT Ext Connect, MST turbo intake pipe, MST Cold Air Intake, JB4 on Map 2 with Catless DP produces awesome performance in Sport.
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01-12-2006, 06:05 AM	#8
davinet78 Lieutenant Colonel 28 Rep 1,832 Posts Drives: bmw e90 320d Join Date: Jun 2005 Location: gibraltar(europe) iTrader: (0) Garage List 2005 bmw 320d E90 [0.00]	when i go at high speeds im always with the windows closed __________________ e90 320d,arktis,lumber support, hifi speaker, alarm, dakota beige, 162 18", xenon with washer spray,window chrome trimmings, professional radio, 6 cd changer wood trimmings 6 speed manual.
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01-12-2006, 06:52 AM	#9
LEDZEP Lieutenant General 418 Rep 12,276 Posts Drives: 2009 E70 & 2011 F25 Join Date: Jun 2005 Location: Area 51 iTrader: (0) Garage List 2011 X3 35i M Sport [7.62] 2009 X5 M Sport [0.00] 2007 328xi E90 [0.00] 2006 325xiT E91 [0.00]	This is common in any car with a sunroof. The air is trying to enter the car and aspirate at the same time and the pressure goes berzerk. Putting the rear windows down about 1" each generally takes care of the problem. __________________ I think it is bad luck to be superstitious
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01-12-2006, 07:12 AM	#10
325 Baller Colonel 264 Rep 2,576 Posts Drives: X3 28i Join Date: Oct 2005 Location: Boca Raton, Florida iTrader: (1) Garage List 2006 325i [0.00]	ya i hate that noise. before i got my car and my fat friend beat me up for shotgun (not literally) i would sit in the backseat of my other friends car and that noise is killer. it hurts sooo bad, i wanted to kill myself. lol __________________ ----------------------------------------------------
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01-12-2006, 07:27 AM	#11
jcoo085 Lieutenant 43 Rep 463 Posts Drives: E90 320d Join Date: Sep 2005 Location: Stuttgart, Germany iTrader: (0) Garage List 2005 320d [0.00]	Yup. Sounds like buffeting caused by pressure differences. My previous cars had this problem when only 1 window was open and it was more pronounced when it was a rear window. I've had the sunroof open on the autobahn at about 140-150km/h and it has been pretty quiet compared to other sunroof equipped cars. __________________ E90 320d - Black Ext/Fluid Grey Int \| Steptronic \| Business Navigation \| PDC \| Sunroof \| Alarm Exterior Pictures \| Interior Pictures \| Video
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01-12-2006, 07:37 AM	#12
eleven24 Foppa! 29 Rep 214 Posts Drives: 2018 X5 xDrive35i Join Date: Apr 2005 Location: Furlong, PA iTrader: (0)	That's happened in every car I've ever been in. It's the same effect as blowing across the top of the bottle & getting a whistling sound.
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01-12-2006, 09:05 AM	#13
espo Captain 12 Rep 715 Posts Drives: 2014 M235i Join Date: Sep 2005 Location: Sugar Land TX iTrader: (0)	Try this one... Open the sun roof and fold down the rear seats... Talk about revirberation (sp?). This first time this happend in my old 325 I thought the car was going to blow up or something. __________________ E46 325xi Oxford Green/Sand Leatherette/Myrtle Wood Auto ZCW - Retired E90 330xi Mystic Blue/Black Leather/Aluminum 6sp Manual ZSP/ZPP/ZCW/CA - Retired F22 M235i Mineral Gray/Red Leather/Aluminum 6sp Manual ZPP/ZTP
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01-12-2006, 09:23 AM	#14
ward Major General 155 Rep 6,158 Posts Drives: F Join Date: May 2005 Location: T iTrader: (0)	I don't think resonance should happen in a BMW demand a new car!!
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