Rattles caused by Excessive Body Flex/ poor torsional rigidity

grey · #1 06-05-2009, 03:05 AM

HI,

I have read a lot of threads relating to rattles and squeaks but havent come across any that mentions that it could have been due to some abnormal body flexing of the E70.
The BMW E70 is supposed to have a very rigid body structure (torsional body stiffness) compared to a lot of other vehicles.
only after 4 months of purchase, my A-pillar trims, B-pillar trims, tailgate they all make a very unconfortable noise every time i drive over uneven ramps at shopping malls, etc.

I tested it by putting a wedge on the front right side wheel another on the rear-left side wheel and drive over it to simulate a body-flex and the above mentioned pillars all makes this unconfortable noise. while the car is on the wedge, slightly opened the front door and tested close it softly, and it would close softly.

is anyone else experiencing noises coming due the flexing of the body? or is it just mine?

the E70 is supposed to have extremely good torsional rigidity

YouTube - BMW E70 X5 Technical Demo

check for "rigid":
3.0si and 3.0si Executive Models Flesh Out BMW X5 Range - AutoWeb News
BMW X5 5-dr wagon range - First drive: BMW's new X5 raises the bar - again - New Models
BimmerFile Archive 10 Years of the BMW X5
2008 BMW X5 Pricing and Information | Conceptcarz.com (15% increase in torsional rigidity)

cmyX6go · #2 06-05-2009, 04:50 AM

The only squeaks I get are from the tailgate in the extreme cold. No noises from the pillars. Once the temperature warms up, I'm good to go.

I have her 18 months and about 19,000 miles

Roadster · #3 06-05-2009, 04:59 AM

the flexing of my E70 is a lot less than my previous E61, that's for sure
and no rattles or squeaks other than a little one in the trunk, but only when cold in the vehicle...

grey · #4 06-05-2009, 05:42 AM

Thanks for your input guys. Do you think having the panorama sunroof may increase the flexing of the body structure?

I'm going to take mine to the dealer in 3 days. Let's see what they come up with.

cmyX6go · #5 06-05-2009, 05:45 AM

Quote:

Originally Posted by grey

Thanks for your input guys. Do you think having the panorama sunroof may increase the flexing of the body structure?

I'm going to take mine to the dealer in 3 days. Let's see what they come up with.

Nope, I have the pano roof too. Good luck.

jimsaq · #6 06-05-2009, 06:07 AM

I have the same thing, you can hear it twisting and creaking whenever I go over curbs/driveways etc on an angle - I've never tested the doors while in this position though

I did the same as you, I thought back to all the videos I'd watched while waiting for my car to be built and recalled them raving on about how awesome the torsional rigidity was

Roadster · #7 06-05-2009, 07:39 AM

the squeaking was much better after I had the torsion bars properly tightened on the E61, you might want to have your dealer check up on this

FSETH · #8 06-05-2009, 08:53 AM

I don't have an e70, but that doesn't sound normal. You should not be getting sound from body flex. As you said the e70 is substantailly stiffer than an e53 and even more rigid that the original e30 race car with full roll cage.

Zoich · #9 06-05-2009, 12:39 PM

[QUOTE=grey;627744]

only after 4 months of purchase, my A-pillar trims, B-pillar trims, tailgate they all make a very unconfortable noise every time i drive over uneven ramps at shopping malls, etc.

[QUOTE]

Are you sure it's not the cheap plastic A/B-pillar trims that's creaking? If so it's fairly normal. Yes, BMW resorted to cheap plastic material. When the weather got warm from winter, it started doing so. I brought it up with my dealer, they removed both pieces and applied felt tape behind. That has helped tremendously. From time to time a huge rattle would still cause them to creak, but no where near just normal driving. Give the plastic a pillars a squeeze (toward the base) you can easily reproduce the noise.

rh71 · #10 06-05-2009, 01:48 PM

I started an "axle creaking" thread and this seems similar. No other parts seem to creak though except for something on the underside. I rode while the tech tried to duplicate it yesterday but we got nothing after going through all kinds of driveways, speed bumps, etc. He supposedly checked the suspension after we got back and still nothing. I haven't heard it again yet but I know I will... this was the 2nd time they found nothing, but I always hear it going up my driveway and a few more around here. He explained that when we're turning in/out of a driveway at an angle, that's when the flex is greatest and *some* noise is to be expected. I suppose as long as it's not a mechanical part going bad, it's all good.