bmwm750

Recently, my A8 has started to make a crunching/ squeaking sound. It is only pronounced under low speed compression, and only does it from a "cold" start (it's worst if the car sits at the airport for a day or two or three, but once I drive a few miles it pretty much completely goes away). It makes noise over a low speed speed bump, or dip (thus low speed compression), but I can't make it make noise by making hard S-turns at 30MPH, loading up each side, and it doesn't make any noise when hitting manholes.

Given that it goes away with a little bit of "use," I'm thinking a bushing somewhere, but I haven't had a chance to go dig around yet.

There doesn't seem to be any noticeable play in anything from a driver perspective, but obviously, something is worn.

MP4.2+6.0

in this order:

1. Front upper control arm inner bushings-- look for distortion, cracking and ultimately tear out. This is basically a when, not if, on any of the heavier Audi's w/ this general design. if you are at 60-75K miles, likely visibly worn by then.

2. Lower links that tie front roll bar to lower suspension -- look for distortion and elongation in bushing area. Will wear some w/ miles.

3. Rubber bushings on roll bar where it bolts up to body; can last a long time, but if it gets oil/grease soaked or some other fluke, could explain your noise.

4. Most anything left in suspension; can spray any selective suspect areas w/ silicone and see if creaking subsides; if so, you have your suspect part.

mishar

+1

But I would almost bet that #1 is the culprit.

JohnnyJ A6Q

It's the hood seal in cold weather, pop your hood one stage and drive and listen. lube it.
it's the body flex

snapdragon

For me it is #3. I just douse it in silicone spray every 6 months and it stops. You have to buy a whole new ARB to cure it as the bushes are bonded on.

Brozee

I have this on both my A8's. Mind going into more detail exactly where it is/ where to spray. Possibly a picture if possible?

McBucky

I had the same issue (winter only) when passing over a depression a few blocks from my home on cold mornings. Kind of a "scrunching" sound that happened every day but only when the car was cold. The dealer would lubricate the upper control arm bushings when I would complain and that seemed to diminish the problem. A deeper fix would be expensive I'm sure. It was (no longer have the S 8) frustrating when that was the only car I owned that would "scrunch" when going over that same depression. McBucky

snapdragon

Sadly, you have to remove the plastic undertray, then find the roll bar, a shiny black ~30mm thick bar across the width of the car behind the front wheels. There are bushes as in the photo below. I use silicone spray in an aerosol with a straw and try and get it between the rubber and metal in the join.

http://www.ebay.co.uk/itm/Audi-A8-D3...-/130592433684

mishar

That dealer is crook. Lubricating busted bushings takes care of a sound for some time but doesn't repair anything.

bmwm750

My guess was the upper control arm bushings, but I had thought about sway bar bushings being a possible idea. I had not thought of the hood, however....

I'm off for a few days after this week, so I guess it'll be time to go look and play....