Things that have caused clunks in my 250,000 miles of urS6 ownership in order of most common to least common:
- worn tie rod end
- worn outer stabilizer bush (2)
- worn top suspension strut bearing (36)
- worn track arm (bushing and/or ball joint) (1/3)
- dead shock absorber (43)
- worn tie rod inner end
- loose top nut due to previous owner! (39)
- loose wheel nuts due to previous owner!
- worn inner stabilizer bush (21)

Not sure if I've ever needed to replace any inner stabilizer bushes. They're not expensive, so I've replaced them a couple of times 'just in case'. Similarly, not sure if I've ever needed to replace the ball bearing (32). The ones I've taken out always seemed to be still functioning.

Outer stabilizer bushes take a bit of a hammering in our heavy cars. Again, they're not expensive - just replace them whenever you've got it all apart. The ones you take out will almost certainly be looking tired.

If any ball joint moves easily, then replace it.

Get someone to wiggle the steering wheel while you stare at the strut bearings, tie rods (both ends), and track arms. Replace any part that shows play.

If you can get it to clunk at will with the car stationary, then you should be able to follow the noise/movement and find the part/parts.

Do these cars have a preload adjustment on the rack? That used to be a common cause of clunking on VWs.

Last time I had a clunk that I couldn't locate, I brought the car to my local friendly MOT (annual car test in the UK) man. He stuck it up on a ramp and spent half an hour wriggling and prying everything in sight until he found a loose nut and a worn bushing - no charge!

Good luck!

Paul

 

See attached photo - spot the bad mounting!

Previous owner had some suspension work done, and the mechanic didn't bother tightening the top nut. Car was amazing to drive - it could change lane with no warning, and before you could work out what had happened, it could change back again. PO also had it fitted with 255/40/17 tyres, and the roads round here aren't great. It's now on 225/50/16 and ever so nice to drive.

That car also had a badly worn tie rod - both outer and inner ends, and a worn track arm (outer ball joint and inner bushing) - all on the same side! If I can find the bits, I'll photo them so Dave can add them to his collection!

Paul

 

Paul: Too funny. I see your photo and go OOooo!! OOoo!! Good photo. Must save. (But it does look a bit familiar). Anyway, I right click on the photo and do SAVE AS, find my UrS Front Suspension photo folder and, sure enough, I have previously saved your photo and probably incorporated it into a front suspension post. So thanks. (I'll go find that post and update it with a "Courtesy of Paul Heneghan" notation.

Keep the photos coming.

Dave F.

 

Update #2: Had oil & brake fluid change today and while on lift my mechanic (different shop that suspension/alignment shop) noticed a couple of things. 1) Paint on upper coils of springs is wearing off @ top & bottom thus coils are "banging" into one another on compression. Paint on the side of the very top coil is rubbing off. 2) At the moment the lift got the car off the shop's floor (suspension fully extended) the mechanic heard a pop...believes the upper most coil is hanging up in the coil directly below (as evidenced by paint rubbed off on side of upper coil) thus creating the noise. As I recall the previous set of HR frt. springs had a flexible vinyl tube wrap around a few upper coils, the replacement (under HR warranty) HR's do not. Perhaps this wrap prevented the upper coil from hanging up in coil directly below + provided some amount of cushioning.

I called HR in WA state to discuss this noise problem and the absence of the vinyl wrap. Was told that when replacement springs are ordered for cars driven in "winter states" (I'm in SE Ohio) the springs are shipped without the vinyl wrap. Evidently the vinyl has been found to cause entrapment of moisture/snow & ice melting chemicals thus leading to eventual spring failure/breakage. Guess this makes some sense but would seem spray being kicked up from driving in rain could also be an issue in non-Winter locales. Going to alignment shop tomorrow for further investigation into this noise problem.

Shop today looked at tightness of suspension bolts, etc. and everything appeared OK.

Any further thoughts?

 

Update #3. To refresh memories S6 is a 95.5 w/ 139,600 miles. Front Bilstein strut inserts replaced yesterday w/ new Bilsteins (B8 Sport). Clunking/banging noise gone. Old Bilsteins were installed 10/2011 and had 66K miles on them; are now on their way back to Bilstein per terms of their original Owner warranty.

Still getting some noise from frt right side but nothing like it was. Could this be considered "normal" for a 17 yr old car that's been lowered. I've read that there have been some issues with earlier C4 S6s in regards to steering rack working loose, is this an issue w/ late model S6s? Its about the only thing that's yet to be investigated in tracking down this problem.

 

There was an issue with the left hand side (intake manifold side) steering rack mount cracking due to metal fatigue. This can be inspected by removing the left front wheel (car properly blocked up) and poking your head in the wheel well with a light while someone turns the steering wheel (engine on to power the PS pump). Look for movement at the mounting bracket.

 

I think I have this issue - it creaks a little when turning out of driveways etc - don't notice it while driving

Here's an old picture illustrating -

 

Can you post a larger photo. That thumbnail is hard to see.

 

Not sure what kind of Bilsteins you have, but I went to Konis because the Bilsteins had play inside the shock tube. Not sure if the dealership didn't install them correctly or what, since the Konis, fronts are much more quiet.

I also had an H&R spring break (wrapped in vinyl). I haven't looked closely at the replacement, but I think it still had vinyl on it.

 

Sorry, I can't find a larger version - I copied that from somewhere else a couple years ago