Bob T

Since before day one(When I test drove the car) I noticed a slight vibration between 68 and 74 mph. I do about 50% of my driving within this range, So it is irritating. None-the-less , I had the dealership make note of it while I was still in the thinking of buying stage. I also noted to them the problem with the button moulding for the sunroof at this time(my car goes in for both issues tomorrow at 7:30) . I rotated the right front(where I believe the wobble is originating) and the right rear. Did not do much of anything. The dealership claims that no-one except a couple salesmen ever drove the car(up until I test drove it) and no-one but a mechanic after I bought it. They also did not notice any vibration or wobble from the front end. Any Ideas ? Is this typical of a front wheel drive ? I have never driven a front wheel drive since I was in college and my dad had a turbo Beretta GT. And that was for like 10 miles when I was home on break. I have always been a Camaro , Firebird person . I checked out the front end for any wear/paint gone/grease/moved boot/ungreased zirk fittings/ect and found nothing strange to the average person.
I will take any ideas with me tomorrow , Also thanks ahead of time and I will post what it is/was(hopefully) once there is a diagnosis.

LTSRAPCON

Mine does same thing, but only with a cross-wind. No wind, no problem.

Bob T

When I was in last I had the dealership try re-balancing the tires. The car still does it. Except now I have a small chip/gouge in my front left wheel . Probably from removing the wheel weight (old one). But of course. That was there, They did not even touch the wheel there !
So , my solution is to drive either faster or slower than that range of speed. Oh well...
What can I expect ? Small town
One thing though , When I make a sorta hard left and begin to accelerate(not hard on the throttle but like getting onto the express way) occasionally it will sound like a thump,thump,thump, that will stop either when I let off the gas a bit ot decrease the radius of the turn. I am so unfamiliar with front wheel drive ,I assume it is associated to the wobble. I went to FL on Vacation a couple weeks ago and had a brand new(800 miles) Saturn Ion with a 2.2. Niether problem could be duplicated , And trust me , I tried on a backroad by the Kennedy Space Center !
'nuff said,

Permafried-

I'm not sure if it'll really help me come up with any ideas but where exactly do you feel the wobble? Is it through the car or just through the steering wheel? I've got a few ideas and some of the things you checked out have removed others from the list but maybe we can narrow it down since your service department doesn't seem to have any ideas .

Permafried-

Bob T

The vibration is in the brake pedal(if you touch it with your foot-no,not pressing it-just touch it with the tip of your foot),the steering wheel seems to wobble left to right (about 1/8 "- not violent -but noticable) and my rear view mirror vibrates about the same amount as when you listen to a good song at about 1/3 of the volume.If I speed up it lessens until it finally smoothes out . The same if I slow down.
Thanks for reading and helping,

vB00STw

JW...at 68 - 74, is the car at high rpms?

Permafried-

I used to have a similar problem on my Cavalier and it was the rotors being warped and my calipers weren't calibrated correctly. It wasn't so much my mirror wobbling but I definitely felt it in the brakes...I'm assuming they already look at this though??

Permafried-

Bob T

No , not really.
It is about 8-10 mph above what I feel is the sweet spot for best mileage.
I have done some pretty intensive computer watching and taking notes. And I have come up with 59-62 MPH is when I get the best mileage. The car still gets about 92-94% of best mileage at 75MPH . I consistently get 29 -31 MPG with my SS. But I am an old fart that drives 70 miles each way to work and all but 2 miles are either highway or expressway. So my average speed on the computer is like 54-57 mph all the time.
The dealership I bought the car from thinks I am messing with them with the mileage achievements.
I really like the car.
Thanks for looking...
*******
The brakes are not warped ,or overheated. They checked that out on Friday.
*******
Off the subject , I have to find a WI Cobalt owner that want to sell their stock tires for a reasonable price. Winter is coming...

fljohnboy

Your car should not vibrate at all. Ask the dealer if their wheel balancer is a road force balancer. The road force balancer will detect any out of roundness, flatspots on tires and whatever applies to wheels/tires. I had a problem like this on another car and I took it to Discounttire. They roadforced the wheels and found 1 tire with a slight flat spot. Sometimes they have to break the bead on the tire and change the position of the tire on the rim. When I went to Discount I told the guy my problem and they spent a lot of time with the tires. They charge $10 a wheel.

codyss

Balancing these wheels require alot of knowledge.

The Cobalt SS 18" rim has no outer rim band so standard weights are not used. You must use stick on weights.

There are two ways to balance them:

1) Use standard balance settings and use normal weights on the inner rim band and then
use stick on weights palced as close to the outside as possible.

2) Use static balance settings and use normal weights on the inside rim band.

Option #1 will be a better balance than #2 but some places cannot figure out #1.

But if you problem is felt in the brake pedal and steering it is the brakes.

Bob T

The dealer has a traditional machine. It is a 20 year old shop(the building,not the business) that basically only has the minimum GM upgrades.
As far as the wheel weights.....They put them on just about an inch inside the hole in the wheel(you know, the space not occupied by the 5 spokes). They are not way inside on the inner lip.
Like I said earlier, I rented a 2005 Saturn Ion and had no problems....at any speed up to 78-79 mph(that is all the faster I would go because I heard they can check out and see if you went 80 or above at the rental shop).
It is not a scary wobble ,or wiggle, or shimmy (however you want to describe it), But it is something I am concerned about. Thanks,

Permafried-

Hopefully you still check up on the forums occasion but I just ran into this on .com and thought it might be worth looking into:

"Well, my car was in the shop for the past two days because there was a rattle in my steering wheel that was driving me up a wall. they had to replace the pinon (sp) and pretty much everything except for my steering wheel they had get a front end alignment... wow it's so nice now! Ever since I bought the car I just thought it didn't handle very nice and I always had a vibration in the wheel, but now that they fixed it it is wonderful."

I also asked if there was any vibration in the brake pedal but the response was no. I'm sure the alignment has been checked but have they also inspected the entire steering column...something loose in there could be causing your wheels to wobble just slightly perhaps...not real sure just thought (since I somehow randomly remembered this thread ) I'd provide you with another possible option . Since it only happens between certain speeds I'm wondering if it could have something to do with ( assuming I remember my physics from grade 12 ) harmonics and ressonance...kind of like a rattle in your vehicle only when at certain speeds just slightly different.

Permafried-

JapEatr

iTrader: (9)

well said on the balance deal

the dynamic(2 wieghts-inner/outer) is the best

sslick406

When I worked in the shop I encountered this alot. Could be a number of factors but most likely b/c of the Static balance. Having all the weights on the inside does not provide as good of a balance as would a standard balance method w/ weights inside and out. I have the same Problem on my '88 Monte SS w/ AR Torq Thrust's b/c I didn't want to wheel weights on the outside.

Bob T

I had the brake booster replaced and the brake "switch" adjusted and between that and having the tires rotated(while getting an oil change too while it was there anyways) all seems well. I am alot happier and my mileage is going back where it belongs. Thanks all.

Permafried-

Awesome glad to hear you got everything fixed .

Permafried-