- Audi A6 C6 Suspension Performance Diagnostic Guide<br>Guide to diagnose trouble and recommended solutions.
Source of front suspension noise/creak (recent full strut/control arm update)
I recently (1 month ago) installed the following new items:
1. All front control arms/tie rods/sway bar links/sway bushings (febi/bilstein)
2. Bilstein HD shocks
3. Stock upper strut mounts
Everything was torqued to spec., with the car on the ground. I've checked and rechecked every bolt just to make sure. At one point I even pulled the shock assemblies out of the car to check the bolt which connects the shock to the upper strut mount. That was the only bolt I couldn't get to when checking all of the torque values. I also checked to make sure the springs were properly seated in the lower and upper rubber grommets (not sure what else to call these). The control arms are tight and don't appear to be defective. Tie rods are tight as well.
The noise is a typical creaking noise that is heard when going over light oscillations in the road. Amplified during light braking. It wasn't there for the first 200 miles or so after the whole setup was installed. One trip through Long Islands' rough roads brought the sound out. Thats when I started to check all the bolts for proper torque and whatnot.
The only thing I didn't replace were the rubber grommets at either end of the springs, they looked fine to me. I took a look at the springs when the car is on the ground and it doesn't look like they're touching anything but the rubber grommets. The only thing that seemed a bit odd to me is that the lower portion of the spring is hanging over part of the lower spring support plate. Even so, the spring isn't touching the support plate.
I can also recreate the noise by moving the steering wheel a few degrees back and forth when the car is stopped. The creaking only happens a few degrees off center.
I'm not really sure how to diagnose the issue at this point. I've read some posts about using a lubricant on the rubber parts but I'm not sure where to start. Is it just a matter of letting the rubber parts "settle"? Should I try to rotate the springs/grommets a few degrees? Does it matter how the springs are rotated with respect to the strut?
Thanks for any help, I'm confused at this point (if you couldn't tell already)
One more symptom. If the car is in park and you turn the wheel a few degrees to the left and then slowly rock the wheel about 5 degrees clockwise/counterclockwise the noise can be heard. I did this with the car off as well and the noise is definitely on the drivers side however I just can't seem to isolate where from.
Any ideas would be greatly appreciated.
Although I'd installed all new Febi/Bilstein controls arms, that were stamped "Germany", it turns out the upper front drivers side control arm has a bad rubber bushing. Guess thats my bad luck...
In the end I diagnosed this as the case by grabbing the control arms with my hands while someone else pushed the car up and down to make the creaking noise. You could clearly feel that this control arm was the source of the noise. Once I get a the replacement, I'll try and take some closeup pictures of the bad arm. Looking at it while on the car, everything looks perfect, no metal-metal contact, no huge cracks in the rubber.
Has anyone ever encountered a control arm that goes bad about 2k miles after installation? I know if I torqued the down wrong then this could be the case, but I was very careful to put the car down on the ground before torquing the bolts...
Long story short, new controls arms can be defective from the factory.
Inspecting the old control arm you can't really see a thing wrong with it. I was going to take pictures but I don't think it will do any good. Something about the construction of the rubber bushing must mean it has multiple layers such that the outside can look good, but something on the inside is bad.
I hope the other 7 control arms don't fail early...
Only thing I can think is that is somehow came loose during the first install and rode on the bolt long enough to carve those groove. I just don't see why it kept on creaking after I checked the tightness afterwards, at the point the arm should have been sandwiched between the mount tight enough to prevent any rotation. Oh well, doesn't matter now since the car is quiet...
Just hope it helps others in the future to diagnose the myriad of reasons the front end makes noise!
Trending Topics
Long story short, new controls arms can be defective from the factory.
Inspecting the old control arm you can't really see a thing wrong with it. I was going to take pictures but I don't think it will do any good. Something about the construction of the rubber bushing must mean it has multiple layers such that the outside can look good, but something on the inside is bad.
I hope the other 7 control arms don't fail early...
Bringing Audi to Life for Audi Fans
Although I'd installed all new Febi/Bilstein controls arms, that were stamped "Germany", it turns out the upper front drivers side control arm has a bad rubber bushing. Guess thats my bad luck...
In the end I diagnosed this as the case by grabbing the control arms with my hands while someone else pushed the car up and down to make the creaking noise. You could clearly feel that this control arm was the source of the noise. Once I get a the replacement, I'll try and take some closeup pictures of the bad arm. Looking at it while on the car, everything looks perfect, no metal-metal contact, no huge cracks in the rubber.
Has anyone ever encountered a control arm that goes bad about 2k miles after installation? I know if I torqued the down wrong then this could be the case, but I was very careful to put the car down on the ground before torquing the bolts...
I give up
I've gone through 3 sets of arms at 175k miles. I'll live with the creak. If my tire falls off I'll just drive it in to the lake
upper and lower control arms worst set up on a car. Put struts with springs and wishbone suspension. That's the best set up
Germans over engineer everything





