A few months ago I bought a 2001 A6. I replaced the brake pads and rotors, and then all the front end control arms and outer tie-rod ends. I also cleaned and re-greased the outer front CV joints.

The car drives and handles fine, has new tires, and no steering fluid leaks. But when I hit a bump or patch of rough road, there's an annoying rattle that sounds like it's coming from the front left side.

The belly pan is missing, so I thought it might be the springy bracket hitting the sub-frame. Took off the bracket and the noise persists

If I apply the brakes, the noise goes away until I take my foot off the pedal.

Any ideas? A shop told my wife it could be the steering rack. Really?

Thanks!

 

What brand controls arms did you install? What brand of brake pads? Have you replaced the inner tie rod ends? Did you replace the sway bar end links and bushings?

Bob

 

I got the control arm kit from fpcgroton.com (aftermarket). I did replace the sway bar links, but didn't touch the sway bar bushings because they didn't show obvious wear (no cracks, bulges, or play). The original control arms all looked fine except for the upper left front. I figured I might as well replace them all since I was pulling the drive shafts to replace the CV boots.

I admit this is my first time messing with control arms, but I didn't have any trouble doing the work. The biggest hassle was loading the suspension to curb weight prior to final torque.

The brake pads and rotors were Duralast from Autozone.

Hope my tight budget didn't set me up for failure.

Larry

 

Broken front struts maybe? My old Oldsmobile Intrigue would rattle from the back side when the strut was broken.

 

Forgot to say I didn't replace the inner TRE. I didn't feel play in the tie rod while doing the outer TRE, but I don't know if that's a good indication that the inner joints are good.

 

I had the struts out and they seemed fine. No play or leaking oil. I've also heard that coil springs can have pieces break off and cause rattle, but I inspected my springs and strut bushings before re-install.

Wish I could mount a camcorder aimed at the suspension while I drive over rough road!

 

Guess I'm gonna bite the bullet, buy a new rack and hope for the best.

 

Never heard of a rack failure that would cause a rattle. Rack failures on Audis are usually leaks. El-cheapo control arms are, however, a known issue. Did you buy FCP's el-cheapo kit or did you search first and follow everyone else's recommendations? Lower rears fail early and fail often and this could the source of your clunk (it will be a clunk or knock more than a rattle).

BTW, Audi ownership and tight budget are incompatable. You need to rethink one or the other.

Bob

 

Thanks for the advice Bob.

Believe me I am rethinking the Audi vs. tight budget issue. I bought the A6 under pressure to get a car in two days --family medical issue, long car trip, long story.

I admit I must not have done a proper search on this forum because I didn't see everyone elses recommendations. I know I searched the web quite a bit and didn't find good advice. The only control arm in obvious need of replacement was the left front upper.

I got the cheapest kit, though I doubt even those control arms would fail in a couple weeks. The sound is definitely more a rattle. I didn't notice it at first because we had hot weather and drove with the windows up and AC full blast. The noise is only audible with the windows down.

 

One more suggestion:
When you replaced the control arms, did you drop the hub/knuckle or bent the brake dust cover? If it just a millimeter away from the rotor it can rattle against it through vibration or bumps.
I did that stupid mistake when I replaced my control arms and it actually was so close I had this grinding noise all the time, unless I actually hit a bump.
I didn't want to spend the money for a new dust cover, so I just bent it backwards (away from the wheel) and it works just fine, not like it's a vital part of the brakes or suspension when it is slightly bend.