wheel balance, breaks or both?
 

I have a problem with a vibration though the steering wheel and through the break pedal when breaking. The more noticeable of these two being the vibration thought the steering wheel. Now here is where thing get complicated.



When I am driving at any speed I can feel a vibration though the wheel and it does vary with vehicle speed, less noticeable at slower (0-45mph) and faster speeds (70+) and at the wheel balancing speed of 55-60mph I have a very slight but noticeable rock when I take my hand off the wheel. This kind of points towards the cause being an out of balance wheel, however I made a note of where the wheel weights were when I had 4 new tires put on. I know I have not lost any weights, or scraped a wheel on a curb. Do you know of any reason why a tire would be out of balance over time?



In addition as I said there is also a very slight vibration coming thought the break pedal when breaking. I did take it to a mechanic to have the rotors checked and he said that the rotors were very slightly warped- however it was only very slight and not enough to concern him. He also stated that if I could deal with the vibration that I would not be harming anything in the short term so long as it did not get any worse. His prognosis that the rotors were warped was based on him seeing heat spots on the surface of the rotors. However when I looked at the rotors myself later I could not see these “spots” but there are dark bands on the rotors, which to my knowledge is normal. What he was telling me did not seam to be adding up so I wanted to get your take on what the root cause of the problem could be, any ideas? Wheel imbalance, warped rotors or both? Also how soon do I have to act on this? I only drive the car about 14 miles a day and I can keep usage to a minimum by using my wife's car is required.

Thanks
James

do you have hubcentric wheels on your car?

I have a similar problem. It is due to out of round tires. I can move tires form one position to another and really affect the steering wheel. So much for trying to save a buck on tires....

I have no vibration added when braking, whatsoever.
Bob

If this problem is due to out of round tiers, I would be surprised (but happy). I have continentals on my car at near $100 bucks a pop and all 5 are new. I am going to have the wheels balanced and see if that makes any difference before I look at changing the brakes. (I figure do the cheep things first).

sorry to ask a strange question but that are hub centric wheels?

Thanks for all your help
James

Same for me: ContinentalProContacts. Took them back to Discount Tire yesterday. The manager took one look at them and suggested a different brand. He is ordering two sets of Goodyears hoping to get four good ones out of eight.

This will be the fourth set of tires in four months trying to find a set that doesn't shake the car like a mechanical bull ride!

I believe the A6 is super sensitive to tires. A bit too sensitive, if you ask me.

Bob

Vibration is usually balance or out of round. Pull is alignment. If the vibration from the brakes is minimal, I'd just live with it. The disks have a tendency to warp if they are used hard and then get wet (from braking hard in the rain). It won't hurt anything as long as it is very slight - it's just annoying. Another cause of a brake pulse could be a sticking caliper. If one pad doesn't engage as hard as another because it is sticking, it will cause pulsing.

I agree with the comment that the A6 is sensitive to tires. I stayed with OEM Pirellis for winter and replaced a new set of Coopers with the Conti's because of problems with the Coopers.

If your looking for a sub-par to par tire I can recommend Kuhmo Z-rated. I have had these for a while w/ no problems. Great tire great price (tire rack).

The only negative I can point out is tire wear is a little premature. I believe this is do to the fact that the tires are mounted on a 5000lb quattro monster