Bad rattling sound from front passenger wheel over bumps

[redbat]

Hey all,

So a few days ago I noticed that I was getting a metallic rattling sound whenever I go over a bump. Problem is localized to the right front wheel. It sounds like something came loose, and like the caliper is going to fall off or something. It's kind of nerve-wracking.

I hadn't touched that wheel for months, but after that happened, I replaced the upper control arms, buttoned it up, and it's still making the noise. Scarily, it seems the noise happens LESS when I put the brakes on when going over a bump, which leads me to believe it's caliper or carrier-related. Needless to say, I've got a manual trans, so it's not possible for me to have the brake on all the time, because I don't have three legs (that's not what she said).

I've done some searching, but can't seem to find anything that matches my issue - everything else I could find described noises that occurred when the brakes were applied, not the reverse.

So kinda stumped here. Going to pull the wheel off again this evening and look at it AGAIN, but wanted to see if anyone had some insight into this...

[Mister W]

Loose brake pads? broken retainer clip?

[DeitschFuhrmann]

Missing anti rattle spring.

[redbat]

Clips/springs appear to be there - haven't had a chance to take everything off yet, but it looks like the carrier or caliper is banging into the rotor - I can see a line where it's hitting. Also, the pads are in contact with the rotor at all times, which would explain why acceleration started to suck at about that time.

Yay. Will update when I have more information, but will take any suggestions or ideas in the meantime...

[Azn Ninja]

hope you source it out. I have same issue currently, but for rear right wheel side. only over bumps. sounds like metal bouncing ..

[menace1930]

This may sound like an odd question but are you running Akebono ceramic pads?

[JayDog747]

Check the rubber bushings that the guide pins slide into. This part gets overlooked when replacing the brakes. Just because they look good doesn't mean they operate properly.

[redbat]

This may sound like an odd question but are you running Akebono ceramic pads?

Nope - don't even remember what they are, but they're not those. And they've been installed on the car for almost a year now with no problem. Aaaargh.

Not an odd question, by the way - I saw all the posts about those. :)

[redbat]

Check the rubber bushings that the guide pins slide into. This part gets overlooked when replacing the brakes. Just because they look good doesn't mean they operate properly.

Wouldn't that have been a problem immediately after installation, though? In July it'll have been a year since I did the pads and rotors...

[JayDog747]

Not necessarily. They can go through a couple of brake changes before they should be replaced. Your car is 10yo. Who knows if and when they were replaced last. Like I said, they may have looked "ok" last year but then, here we are today. This was just a suggestion of one thing to look at.

[redbat]

Not necessarily. They can go through a couple of brake changes before they should be replaced. Your car is 10yo. Who knows if and when they were replaced last. Like I said, they may have looked "ok" last year but then, here we are today. This was just a suggestion of one thing to look at.

Thanks, I really appreciate it. I'm going to pull the whole thing off the rotor this weekend and check everything out. To confirm, is what you're talking about the sleeve dealies that have the dust caps on the end? I'm willing to bet they've never been replaced.

[JayDog747]

Yes. I replaced mine with these:

http://www.tyrolsport.com/brakes/tyrolsport-brake-caliper-stiffening-kit-for-vw/audi/

[ihearte30s]

Try to tighten the pinch bolt for the upper arms more. When I installed mine I had a similar noise and I could not figure it out. One day I was checking my pads to make sure they weren't the culprit (for the third time) there was no change. I decided to tighten the bolt. Noise was gone. It didn't sound like a noise the arm would make.

[redbat]

Try to tighten the pinch bolt for the upper arms more. When I installed mine I had a similar noise and I could not figure it out. One day I was checking my pads to make sure they weren't the culprit (for the third time) there was no change. I decided to tighten the bolt. Noise was gone. It didn't sound like a noise the arm would make.

Ok, I'll give that a shot first (I hope that's it), but this noise started happening BEFORE I swapped the upper control arms.

Another thing that it MIGHT be is my passenger-side engine mount, but my understanding is that it would have to be VERY far gone to be making a metal-on-metal sound. I've got a spare for both engine mounts on hand, and that mount IS leaking fluid (reddish stuff on the bottom of the mount, confirmed via visual inspection underneath).

The mount would pretty much have to be super flat AND moving laterally to make a metal rattling sound, I think, but anyone feel free to correct me if I'm wrong about that.

Will be swapping both of those mounts out this weekend, along with the snub mount AND the other set of upper control arms...hopefully one of these things (along with the disassembly of the brake carrier) will solve the issue...

[cooldeke]

My 2008 A4 is doing the same but on the driver's side, I took it to Audi three times, and the last time they had my car for all most two weeks before they came up with my sub frame is cracked which will cost 3,200 dollars to fix. I will take that 3200 and put a down payment on another Audi before I get that fixed.

[ihearte30s]

My 2008 A4 is doing the same but on the driver's side, I took it to Audi three times, and the last time they had my car for all most two weeks before they came up with my sub frame is cracked which will cost 3,200 dollars to fix. I will take that 3200 and put a down payment on another Audi before I get that fixed.

My subframe did this when I first got the car. I bought a subframe from a salvage yard (www.car-part.com) and had a local shop stich weld the seam for $65. Super solid ever since. It's actually really easy to swap, just make sure you replace the 4 long bolts if you ever do it. [up]

[redbat]

Ok, PROBLEM SOLVED.

The issue was the 2 21mm carrier bolts on the back of the carrier. They had somehow rattled themselves loose. My guess is that I went over a really gnarly pothole or something that knocked them loose. Putting on the brakes stopped the carrier from rattling because compressing the piston pushed the caliper assembly back/out against the carrier.

So tightening those 2 bolts fixed the issue. Pro Tip: Once you've got the caliper assembly off the rotor, try moving the carrier. If it moves AT ALL in any direction, tighten those bolts. Especially if you've replaced your own rotors in the past and maybe didn't use a torque wrench [rolleyes] (like me).

I believe the correct torque specs for those bolts is 190nm/140 ft/lb, but need to confirm - for now they're just "guten tight".

[Rahmen]

Just to chime in on a sorta old post...

Had the same problem, read this thread and sure enough, same issue. Two 21MM caliper carrier bolts were loose. Just quickly tightened them (during lunch at work) and rattle stopped immediately. Changed my pads and rotors about a month ago, so makes sense. I'll see if they hold now, may need a more permanent solution than "guten tight" :-)

[Theiceman]

that's why God invented Blue Loctite and Big ass Wrenches .. get a real guy to tighten them next time ;)

[Okedokey]

that's why God invented Blue Loctite and Big ass Wrenches .. get a real guy to tighten them next time ;)

Yep, just did them last night, blue loctite and plenty of torque.

[4.2V8S4]

Missing anti rattle spring.





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[15-NSFW]

I've had the same rattling coming from the front drivers side of my car simply after changing the wheels from factory to aftermarket, I was like wtf! How could simply changing the wheels from 19x8.5 to 19x9.5 cause some type of rattling.

I took the car to a "suspension specialist" who looked over the car & told me that there is no issue with any of the bushes on the control arms & that the noise sounds like it is coming from under the dash or from the steering rack but any idiot can clearly tell that the sound is coming directly from the drivers side wheel well so I put the car up on ramps last night & got a deadweight hammer & started tapping on all the suspension components on both sides to see if there was a difference between any of them & there was a clear difference between the front lower rear control arms on both sides. The drivers side sound tinny & rattled but the passenger side was solid, took me all of 2 minutes to find the difference, I don't know how someone that works on suspension for a living didn't find it

So now it's either replace the front lower rear control arm to chassis bush or it's the heat shielding directly next to it