Vibration through steering

A6 All/ S6 All
#1

So i thought this was originally casued by some badly balanced wheels so my first port of call was getting my wheels refurbished, new tires fitted and road force balanced and i got my alignment done too.

I still get a bad wobble/vibration through the steering at around 120-140kmh.

I did notice and mentioned in another post that the upper most control arm links on each side seemed to have wear starting to show on the bushings. ill take some pics when i have it up on the ramp this coming week.

So where is a good place to start troubleshooting this. Below is what my limited knowledge on these cars think could be the solution:

  1. New control arm kit -  Meyle HD is best option available locally
  2. brake Rotors warped - rears need to be replaced shortly
  3. Bushings/mounts in drivetrain - i have no idea where they are on the s6
  4. Engine mounts - i really hope its not these!
  5. You guys tell me!

Audi dealers are useless here in Ireland and they charge the equivalent of $160 per hour labor, so no way i will waste money with them, and also i have yet to find a good independent shop yet i would trust to work on my car. I have no problem working on the car myself, one good thing i got from years of Subaru ownership!

Any advice would be appreciated.

Dan

Any pointers or recommended starti

#2

That’s a tough one… My control arms/bushing and motor mount were all completely shot, they were in really, REALLY bad shape. And I also had warped rotors. But my car never experienced the vibration you are describing. That doesn’t mean it isn’t caused by any of those things, everyone’s car is different… Does it continue to shake/vibrate even if you let off the throttle and put the car in neutral while driving at speed? If so, I would think that rules out the motor mounts.

#3

I never even thought it was possible to put the car in neutral while driving at speed! i can try that out and see if it changes. I have a long drive coming up this weekend so a good chance to test that an pin point the exact circumstances the vibration appears at.

It is very possible the tire shop didnt balance the wheels correctly though. But i have had to tire places balance them since i got the new tires.

Saying that, third times a charm! There is a VW dealer that did an awesome job on my legacy in the past, with some Hunter alinmen equipment. Maybe it worth visiting them before i start dropping funds replacing parts that are not causing this symptom

#4

Another possible cause could be be wheel hub bearings on the way out? This could turn out to be an expensive annoyance to fix!

#5

from product description this could have the potential to be the cause:

https://www.ecstuning.com/Audi-C6_S6--V10_5.2L/Drivetrain/Mounts/ES390367/

[quote]An often overlooked bit of maintenance, the transmission mounts in your vehicle are an important component to keep your vehicle in top shape. They keep your driveline triangulated and mounted securely. Over the years and exposure to the elements, the rubber in these mounts can degrade.
With bad transmission mounts, excessive vibration and noise is transferred to the cabin. The rubber in the mounts wear out over time and cause too much movement in the drivetrain. Replace them when wear is detected to keep everything tight.
By replacing the mounts, there will be a noticeable improvement in overall driveability. Shifts will be smoother and more precise, idling will be quieter and less shaky, and vibration overall will be greatly reduced. Don’t take a chance on doing damage to your vehicle with broken or worn motor mounts. Replace yours and keep everything under your hood tight.
[/quote]

#6

OK so 4 hour drive today on mostly highway and car just doesn’t feel planted. Vibration at varying speeds from 110-160kmh. Dropped it into neutral on a few occasions and it didn’t help. Car just doesn’t feel stable at speed. I guess I’ll started with the front control arm kit first.

#7

Odds are, even if the control arms aren’t THE problem, they’re still A problem. So I don’t think you’re wasting money by trying that first. With a little luck, hopefully that’s the end of it and you don’t need to try anything else, worst case scenario at least you’ve got a new control arm kit which you undoubtedly would’ve needed soon anyways.

#8

ok well there are some good clues so we have something to start with

a good place to start is with a few questions.

When did this start. Does it get worse with speed and is it only at that one certian speed that this happens.

A few points.
Brake rotors dont warp but they do get brake pad deposits on them and this is something you feel when you hit the brake pedal when your slowing down.

The syspension can be an issue but its not going to be constant and if the road is smooth you shouldnt feel anything as the suspension is going to just be static. The same goes for most mounts as well.

#9

doesn’t sound like the motor mounts. you’ll tend to get more of a thunk when they start going bad. shifts might feel a little harsher as well. an easy way to check is open the hood, car running, put in drive, hold brake, and rev engine. if the engine moves more than an inch, then your mounts are probably on their way out. my engine was moving about 5 to 6 inches on this test, looked like the engine was trying to crawl out of the engine bay, crazy. upon removal, passenger side was in two pieces, hence the large amount of movement.
wasn’t too bad to change the mounts. you will need a cherry picker, or an engine support bar. i want the engine support bar route. i was able to do it without removing the motor brackets, which would have required a lot more things be removed to get to all the bolts. the top bolts of each motor mount are the toughest part. passenger side can be done from under the car. the driver side i had to attack from the top (air box and a few other things had to come out).
if it hasn’t been done, and you’re anywhere near or past 80k, you may want to do them sometime soon.

same thing with suspension bushings. if they haven’t been done, they’re probably starting to go. i did the uppers at about 65k, and the lowers at 80k. both were showing wear and starting to get a little sloppy at that mileage.

as justin pointed out, these probably aren’t your problem, but it’s something you should think about replacing.

#10

To back up froggerS6 you deffinitly want to look at the mounts bad mounts can lead to a ton of other issues that can cause drive train issues including vibration

Dan if you get a chance let us know what you came up with for getting some answers to the few questions I put out. that will help eliminate some possible issues

#11

Thanks for he advice guys, ill check out the engine mounts using the froggers6 method!

Ill get the Meyle HD kit anyway soon this month and just get them done, just pricing the labor charges with local garages to see where to get it done, i cant do much heavy lifting with my messed up neck/spine

The vibration seems to occur on highway around 70-80mph but not always or maybe i just stop noticing after a few minutes while driving. I shortly went up to approx 100mph and it was still there.

Lets start with the control arm kit which is a good starting point and was on my to-do list anyway at arounf the 70K mark