Shaking and shimmy around 80-85 miles per hour

[trfortin69]

Hi all,
I have a shaking and a shimmy around 80-85 mile an hour range and took it to the dealership 3 times for this, all three times they say they can't find anything wrong with it. I've changed from 17in run craps to nice 18 in 264 wheels with brand new regular tires and it does the same thing. Has anyone else witnessed this in their car? Also, what should I do? the dealer said they can't find anything but I know its there, they act like I'm crazy. I tested the coupe and another convertible neither of those cars did this. Or at least I can't remember them doing this. Any advice?

[The Cthulhu]

You must have done a high speed balancing on your wheels once the tires were mounted, but did you check your alignment?

Have them ride with you on the highway so that you can replicate the problem.

[trfortin69]

Originally Posted by The Cthulhu

You must have done a high speed balancing on your wheels once the tires were mounted, but did you check your alignment?

Have them ride with you on the highway so that you can replicate the problem.

I did on the new wheels, also the old wheels (original wheels on the car) and it does the same thing. Also, they did do an alignment as well. So far as both alignment and proper weighting It's all been done. I was hoping once I did this it would go away, it did a little but not all.

[1bonna]

Best bet is to have a technician ride with you so that you can replicate the problem.

[trfortin69]

Originally Posted by comotu1

Best bet is to have a technician ride with you so that you can replicate the problem.

good point, I haven't done that yet

[trfortin69]

I'm convinced I'm experiencing cowl shake. Can anyone argue that or confirm that?

[emtrey]

cowl shake is usually over bumps, uneven surfaces. Cowl shake at that speed would be a bad design flaw..very un-BMW and others would have felt it.

I think you need to get a tech in the car and show him the problem.

[trfortin69]

Originally Posted by emtrey

cowl shake is usually over bumps, uneven surfaces. Cowl shake at that speed would be a bad design flaw..very un-BMW and others would have felt it.

I think you need to get a tech in the car and show him the problem.

hmm, one of the reviews actually mentioned they felt it on 128i convertible, however said it was very minimal but present. I'll try and find the article again

here's the review quote and link

For the first week, we tooled around in the 128i convertible. We will overlook the i-Drive system that comes with the navigation package - an option that we would leave unchecked and figure out something else to do with the $2,100.

Maryland had some fine weather that week so the top was frequently down, something that takes abut 20 seconds and is as easy as pie. There was very little cowl shake and normal conversation was possible inside at most highway speeds.

http://www.marketwatch.com/story/200...5i?dist=msr_10

[trfortin69]

it's also in this article:

http://www.caranddriver.com/reviews/...t_drive_review

[trfortin69]

here's another one from consumer guide, I may be on to something. Says little but still is present.

Rich-looking plastics, lightly padded surfaces, and wood or textured aluminum trim line the interior, and seem in line with prices. The convertible feels impressively stiff for a 4-passenger car, with little cowl shake over bumps. However, one test convertible suffered from an intermittent top-up rattle.

[blklacker]

Yeah that's a problem... cuz the faster I go in my 1er the more planted it feels..

I can take this car up to 140mph and the car feels super..

so re-balance/scope alignment IMO

[RPM90]

Originally Posted by trfortin69

here's another one from consumer guide, I may be on to something. Says little but still is present.

Rich-looking plastics, lightly padded surfaces, and wood or textured aluminum trim line the interior, and seem in line with prices. The convertible feels impressively stiff for a 4-passenger car, with little cowl shake over bumps. However, one test convertible suffered from an intermittent top-up rattle.

ALL convertibles are susceptible to cowl shake, even BMW's.
The 135i vert I tested also had cowl shake. It's normal.
Why are you surprised by the cowl shake though?
Were you expecting it not to have some?
Or, is it really that bad?
If you want bad drive a Mustang vert, the new ones are better.

When you get a convertible you give up some of the overall body rigidity.
Cowl shake is very very common.

[RPM90]

Originally Posted by trfortin69

Hi all,
I have a shaking and a shimmy around 80-85 mile an hour range and took it to the dealership 3 times for this, all three times they say they can't find anything wrong with it. I've changed from 17in run craps to nice 18 in 264 wheels with brand new regular tires and it does the same thing. Has anyone else witnessed this in their car? Also, what should I do? the dealer said they can't find anything but I know its there, they act like I'm crazy. I tested the coupe and another convertible neither of those cars did this. Or at least I can't remember them doing this. Any advice?

I'm confused by your posts.

Ok, you have a vert. You also have a shimmy/shake at high speed.
And, you also have some cowl shake.

Are you describing the 2 problems/issues as the same thing?
You shouldn't. Cowl shake is very common on bumps.

Shimmy/shake, which affects the front steering as the vibes travel through the front components and into the steering wheel, and even to the dash and cowl area. This is typically caused by a bad tire or wheel, or badly done balancing. If the problem appears at a certain speed and then isn't there at a high or lower speed, then go and get your wheels/tires rebalanced.

Alignment won't affect this shaking/shimmy.

The cowl shake is caused due to less structural support that you would have if you had a hard top. The 1 vert does have some of this type of shake. It's simply caused by lack of a top, as in most other verts.

You seem to have 2 different problems that at some point make each issue even more apparent.

[warmtoes]

I've driven up to 100mph and a bit above quite a few times and haven't ever felt a shimmy.

[MOCKBA]

I have the same problem, everything is stock and never touched. First, I know that balance problem happens at 60-65, so it isn't balance related. I do not see 1 wheels have significant wheel diameter difference with other cars so balance shake should happen on the same speed. I also found that problem appears only on asphalt road surface, and never on concrete pavement. So I am thinking toward to design flaw. Generally the problem doesn’t bother me much, it has benefits, if you start accidently speeding, this shimmy behavior tells you, slow down dear.

[cagekicker]

never had that problem.

[RPM90]

Originally Posted by MOCKBA

I have the same problem, everything is stock and never touched. First, I know that balance problem happens at 60-65, so it isn't balance related. I do not see 1 wheels have significant wheel diameter difference with other cars so balance shake should happen on the same speed. I also found that problem appears only on asphalt road surface, and never on concrete pavement. So I am thinking toward to design flaw. Generally the problem doesn’t bother me much, it has benefits, if you start accidently speeding, this shimmy behavior tells you, slow down dear.

It sounds like you may be experiencing "tramlining", which is an odd "vaque" feeling in the ride and steering. It can feel light on certain types of road, especially on surfaces that have grooves in the road, which is to help move water off the roadway. Some tires are much more susceptible to this than others. I think our RFT's are prone to this sensitivity.
I agree that if it is a balance problem, then it should occur no matter the road surface.

I had said before that alignment doesn't cause shake/shimmy.
I need to clear that statement up. It doesn't 'directly' cause the shake, but it can contribute to the problem by creating a condition known as "feathering" of the tire tread. Feathering is a condition where the tread feels rough as you run your palm along the tread, usually down the middle. You can feel that the tread is higher and then lower. IOW, it's undulates. This then can cause a shimmy/shake as well, that is not balance related, but related to the feathering problem. Feathering can be caused by improper alignment.

An "our of round" tire can also cause problems that are nearly impossible to balance out, and the shake can happen at odd speeds, sometimes it can feel smooth as butter, and within 5 miles it starts shaking again, and the cycle repeats. I've also had tires with "shifted belts" that causes similar problems.

A faulty "shock"/damper can also cause some shimmy problems. If the damper has faulty internal valving, then it can't control the spring properly, thus allowing it to undulate in a not controlled manner, which can manifest as a shimmy or shake.
Maybe the OP has this problem?

In my 135i the only shake I've had is when the tires are cold. I get a noticeable shake in the steering wheel for the first 7-10 miles or so.
Then, it all smooths out.
I'm NOT a fan of these RFT's.

[italiantank26]

I think I know what your problem is. First, are there a lot of potholes where you live? If so then this is most likely the issue. Your rims are possible slightly bent from a pothole, and you might not notice it because the damage is so minimal. The same thing happened to me when I got new tires. Because my RFT were so stiff I didn't noticed, but on my new tires I felt a shimmy around 80 mph. Took it to the dealership, and they didn't find anything. Went back to townfair tire, and they resolved the problem right away.

[turner23]

Sorry, it's got nothing to do with your run flats...I drive my 128i with stock 17" run flats and its smooth as butter from 1mph-110mph.

Get an alignment, and make sure its done correctly! A friend of mine bought 4 new tires on his M5; they were aligned and two weeks later he had to replace a tire from premature wear. He took it to a different shop and found out that the previous alignment was off on one of the wheels by 3/4".

[Midgad]

never as much as a shudder here, solid as a rock as all speeds.

[jibaholic101]

my car is as planted at 140 as it is at 35

hypothetically.....

[RPM90]

Originally Posted by turner23

Sorry, it's got nothing to do with your run flats...I drive my 128i with stock 17" run flats and its smooth as butter from 1mph-110mph.

Get an alignment, and make sure its done correctly! A friend of mine bought 4 new tires on his M5; they were aligned and two weeks later he had to replace a tire from premature wear. He took it to a different shop and found out that the previous alignment was off on one of the wheels by 3/4".

Alignment does NOT affect shimmy or shake. It can affect tire wear and cause issue with the tread, which can then cause some shaking or shimmy.

Getting an alignment with tires that are already feathered or worn oddly, will do nothing about the shake/shimmy, as it's not coming from alignment, it's coming from the tires.
Of course, we're assuming that his problem is coming from the tires. ♦