help! after c/o installation, car vibrates for short periods when accelerating

rzm3 · 11-18-2007, 07:45 PM

i recently installed H&R street performance C/O on my 335xi coupe. everything works fine except -

when accelerating full throttle at higher gears (4, 5, 6) and low RPM ~1500-2000, car vibrates (vigorously) for around 0.5 seconds initially. and after the vibration, everything goes back to normal. and no, this is not because i am driving over a bump...

i am a mechanical engineer, so technically speaking, it feels like the new suspension changed the natural frequency of the car, and when the engine is at a certain speed and transmission in a certain gear, the car resonates with the frequency of the engine. thus the entire car vibrates.

any suggestions on what i can change?

stooken · 11-18-2007, 07:46 PM

might want to check if everything is bolted on correctly.

DTM_P0W3R · 11-18-2007, 07:46 PM

Did you drive over a few bumps?

rzm3 · 11-18-2007, 07:57 PM

Quote:

Originally Posted by DTM_P0W3R

Did you drive over a few bumps?

well it has been more than a week since the installation. so yes, lots of bumps

DTM_P0W3R · 11-18-2007, 10:29 PM

well......have u ever been in a sport car/car with coilovers? you feel every bump on the road

wj4 · 11-18-2007, 10:33 PM

If this was bump related..it wouldn't have gone away and would only progress as he picks up speed. I have some friends who have cars that are unbearable over bumps, to the point where you have to support your butt with your hands because it's that stiff.

To the OP, take it to a reputable shop to have the install looked at if you are sure if the coilover. I've helped out with many coilover installs, over 10 easily, and never heard of this though.

rzm3 · 11-18-2007, 10:51 PM

Quote:

Originally Posted by DTM_P0W3R

well......have u ever been in a sport car/car with coilovers? you feel every bump on the road

come on you think i am stupid or something? I can tell the difference between hitting a fuking bump and my car vibrating on its own on a smooth road.

stooken · 11-19-2007, 01:20 AM

Quote:

Originally Posted by rldzhao

come on you think i am stupid or something? I can tell the difference between hitting a fuking bump and my car vibrating on its own on a smooth road.

Babe · 11-19-2007, 05:11 AM

Quote:

Originally Posted by stooken

might want to check if everything is bolted on correctly.

My brother says to have all bolts re-centered and torqued.

XYR03 · 11-19-2007, 11:44 AM

A buddy of mine had that problem with his mini. When we took it off we were missing pieces from the manufacture. We were missing a washer and a bump stop or something like that. The coilovers were sent back and were put on again and they were fine. I blieve you are missing few pieces in the setup. One washer can make a big differnce in the whole suspension so take it off and see whats up. I hope this helps.

335aj · 09-24-2008, 07:33 PM

iam having this same issue. Did you ever solve this problem?

Mr. 5 · 09-24-2008, 08:34 PM

Please tell me you got an allignment after the install.
If not then there's your answer.

My car felt great after my suspension install, but I took it to get it alligned and it was way out.

EDIT
This is from 2007???
I'm wondering if he ever got the alignment.

shane335i · 09-24-2008, 08:49 PM

yeah - it would be nice to hear how he solved the issue!

335aj · 09-24-2008, 08:57 PM

i did get an alignment done, fixed the issue somewhat, but under hard accel, the vibration is still there

11-18-2007, 07:45 PM	#1
rzm3 Moderator 673 Rep 4,737 Posts Drives: E92 M3 Join Date: Aug 2007 Location: USA iTrader: (18)	help! after c/o installation, car vibrates for short periods when accelerating i recently installed H&R street performance C/O on my 335xi coupe. everything works fine except - when accelerating full throttle at higher gears (4, 5, 6) and low RPM ~1500-2000, car vibrates (vigorously) for around 0.5 seconds initially. and after the vibration, everything goes back to normal. and no, this is not because i am driving over a bump... i am a mechanical engineer, so technically speaking, it feels like the new suspension changed the natural frequency of the car, and when the engine is at a certain speed and transmission in a certain gear, the car resonates with the frequency of the engine. thus the entire car vibrates. any suggestions on what i can change? Last edited by rzm3; 11-18-2007 at 11:04 PM..
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11-18-2007, 07:46 PM	#2
stooken Brigadier General 184 Rep 4,244 Posts Drives: E70 X5 Join Date: Apr 2007 Location: NOR*CAL iTrader: (2)	might want to check if everything is bolted on correctly. __________________ 2010 E92 BSM 335i \| M-Sport \| ST Coils \| Linea Corse Lemans \| Cobb AP \| BMS DCI \| Cyba Tips
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11-18-2007, 07:46 PM	#3
DTM_P0W3R Private 14 Rep 91 Posts Drives: Porsche C4-SOLD- Join Date: Nov 2007 Location: 818 Socal LA iTrader: (0)	Did you drive over a few bumps?
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11-18-2007, 10:29 PM	#5
DTM_P0W3R Private 14 Rep 91 Posts Drives: Porsche C4-SOLD- Join Date: Nov 2007 Location: 818 Socal LA iTrader: (0)	well......have u ever been in a sport car/car with coilovers? you feel every bump on the road
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11-18-2007, 10:33 PM	#6
wj4 Major General 335 Rep 7,719 Posts Drives: E90 manual 335i Join Date: Nov 2006 Location: Burbank, CA iTrader: (8)	If this was bump related..it wouldn't have gone away and would only progress as he picks up speed. I have some friends who have cars that are unbearable over bumps, to the point where you have to support your butt with your hands because it's that stiff. To the OP, take it to a reputable shop to have the install looked at if you are sure if the coilover. I've helped out with many coilover installs, over 10 easily, and never heard of this though.
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11-19-2007, 11:44 AM	#10
XYR03 Lieutenant Colonel 123 Rep 1,675 Posts Drives: Cayman S Join Date: Sep 2007 Location: Charlotte, NC iTrader: (6)	A buddy of mine had that problem with his mini. When we took it off we were missing pieces from the manufacture. We were missing a washer and a bump stop or something like that. The coilovers were sent back and were put on again and they were fine. I blieve you are missing few pieces in the setup. One washer can make a big differnce in the whole suspension so take it off and see whats up. I hope this helps. __________________ [SIGPIC]2015-Cayman S (Can't leave bimmerpost) 2009-E92 M3 2005-E46 M3 1998-E36 M3 2007-E92 328i[/SIGPIC]
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09-24-2008, 07:33 PM	#11
335aj Private 6 Rep 94 Posts Drives: beemer n benz Join Date: Sep 2008 Location: Vancouver iTrader: (0)	iam having this same issue. Did you ever solve this problem?
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09-24-2008, 08:34 PM	#12
Mr. 5 Modder Raider 753 Rep 8,633 Posts Drives: M3 Join Date: Apr 2007 Location: Surf City, HB iTrader: (31) Garage List 2007 e90 335i [8.00]	Please tell me you got an allignment after the install. If not then there's your answer. My car felt great after my suspension install, but I took it to get it alligned and it was way out. EDIT This is from 2007??? I'm wondering if he ever got the alignment. __________________ e36 M3 Coupe, e36 325i Sedan e90 335i--SOLD Best 60-130-------------9.15 Seconds------------------WWW.MR5RACING.COM
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09-24-2008, 08:49 PM	#13
shane335i Second Lieutenant 6 Rep 207 Posts Drives: 2016 BMW M4 Join Date: Sep 2008 Location: Woodside, CA iTrader: (0)	yeah - it would be nice to hear how he solved the issue!
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09-24-2008, 08:57 PM	#14
335aj Private 6 Rep 94 Posts Drives: beemer n benz Join Date: Sep 2008 Location: Vancouver iTrader: (0)	i did get an alignment done, fixed the issue somewhat, but under hard accel, the vibration is still there
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