Noise from rear of car only while driving, can not duplicate noise by bouncing rear of vechicle,replaced rear struts, replaced sway bar links ,everything from trunk removed, sounds like something loose, loud knock or thumping... thanks

check strut or hub

I would tend to believe it's more likely a worn sway bar bushing or link if it's a rattle or a small clunk, if it's a loud clunk probably a strut, try bouncing he back of the car when parked, if you get the clunk probably a strut if only when driving,turning,braking probably just a bushing on the sway bar

Hello Tompwestme.

While it is possible the struts or the upper strut mounts are causing the noise, the far more common, and much cheaper problem, is the sway bar links.
To check them properly a drive on hoist is best as it keeps the sway links at the cars normal ride height.
If you lift the car any other way it puts the links into a different position and may be harder to verify the wear.

The links are like small tie rod ends (a ball inside a socket) and when they wear they become loose and cause an awful racket on bumps.

Also where the sway bar is attached to the body there are rubber bushings that wear and allow the bar to wiggle inside and clunk there too, especially in cooler weather when the rubber gets hard.

Sway bar and bushing noise will be evident on the smallest of bumps whereas the strut mounts will need a little more of a bump to create the noise.
If the upper mounts are the problem your struts at 75k will likely be OK, but to change the mounts they have to come out anyway. So you may need to make a decision at that point if mounts needed.

There are a couple of possible common problems for you.
If you need more help with this problem, please ask me.
Thank you for using FixYa.

KL

The sway bar is connected to the strut via the sway bar link pins which very commoonly go bad and make popping,rattling,and clunking type noises

Yes this sounds like A sway bar condition and yes you can Replace just the links and bushings. I would not replace the sway bar its self unless that is infact what broke. I hope this helps you out. i would appreciate it if you would rate me.
thank you
Aaron

its sounds like possible stabilizer bar links also known as sway bar links. some links have a ball and socket style(more than likely yours are) not sure what theyll cost for an audi a easy test just grab a hold of the sway bar and shake it up and down you should feel any slack and might be able to re create the noise but youll have to be under the vehicle to really shake it . although its possible you need struts and/or mounts if its been a while or never done bouncing the car up and down with the hood open should show the strut bouncing if the mounts bad hope this helps good luck

could be struts or a rear sway bar thats bad

Shocks/struts need to be replaced.

Do not heat or bend any suspension parts. Big no-no. If it's all touching and out of whack, check for possible bent frame. Body-shop that did the past work might have overlooked the frame being bent. All measurements start with a straight frame.Then go after the individual hitch and sway bar.

i assume that this is a sl2 or a sc2 both have a rear sway bar and possibly have binding sway bar links. remove rear wheel and find link that goes from rear sway bar to strut and make sure it is able to pivot. if they are binding they make a lot of noise and need to be replaced