Front end "clunk" noise finally resolved.

[alcatranz518]

Backstory: I've owned my S4 the past several years (bought used with 140k miles on her) and since purchase it had the front end noise. Well no big deal as I planned an entire overhaul. I changed out the entire front suspension and steering last summer with new/ updated parts (034 street compete control arm kit, Hotchkiss sport rs4 sway bars, 034 spherical links, Bilstein yellow struts, and all new hardware), as well as all upgraded drivetrain mounts fron to back (@ 150k miles). Well luckilly the noise was still there, and same as always. A "clunk" style rattle similar to a bad strut or bushing typically at lower speeds (< 60 mph) and on bumps coming from the right side (in addition to the typical "clank" of the pads under initial braking from a bad brake pad spring, but I already know that problem and planned the fix). . So several times I tore the front down, inspected, and re-torqued everything per the Bentley manual with no luck..until...

So I just did the brakes because when I did the overhaul the brakes were at about 80% life. When I did, I bought the caliper stiffener kit Tyrolsport makes (https://www.ecstuning.com/Audi-B7_S4...Kit/ES3138053/) because I had a theory that the noise was the caliper pin bushings being worn and the caliper was rattling on the hardware. All I did was change the pads (OEM), pad springs (OEM), swapped out the pins/ bushings with the stiffener kit, and flushed the fluid.

The noise is gone, I know exactly which roads it would make the noise 100% of the time so since I drive that road twice a day if not more I've been closely paying attention to speed and making sure I hit those same bumps. I can say, I waited 2 weeks testing to make sure before posting this because I know many others here have had this same dilemma and making them nuts too. From the threads I've read it sounds like the same issue. All I can say is give it a try, that kit fixed my issue hopefully will yours too. As for change in brake feel, I can't say I notice any change whatsoever.

[JayDog747]

It will come back when you reach less than 10k miles left on the pads. Ask me how I know.

[alcatranz518]

Do tell sir

[JayDog747]

Been deer done 'dat. I'll be going back to the rubber bushings soon. SS brake lines have a more positive effect than the Tyrolsport kit.

[Myb6_1.8t]

I have a clunk sound coming from left left wheel I've replaced front suspension. I just replaced brakes, thats when sound occurred. Help?????

[q_dubz]

hmmmm

[JayDog747]

Ummm? Well? If you didn't replace the rubber bushings, you can start there. Other wise you can re-torque the suspension. Just make sure you do it at ride height.

[Salvaje]

I have a clunk in mine that has never gone away. Mostly under hard acceleration and hard braking. Feel it clunk right under my foot. Done engine mounts and suspension bushings and control arms. Did it before and after new suspension


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[alcatranz518]

I agree with Jay, replace the bushings and pad springs. If the problem persists, re-torque the suspension and be sure its at ground weighted height when doing so (the height the car is at when sitting on level ground). For instance, my car completely stock is 14.5" from bottom of fender well to center cap (center on center, completely vertical)

[alcatranz518]

I have a clunk in mine that has never gone away. Mostly under hard acceleration and hard braking. Feel it clunk right under my foot. Done engine mounts and suspension bushings and control arms. Did it before and after new suspension


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Have you checked/ re-torqued your subframe hardware? Also something to look at is your exhaust down pipes for interference marks, its possible one of them either came loose (they have a bracket that connects in that area) or the bracket is broke.

[Salvaje]

Have you checked/ re-torqued your subframe hardware? Also something to look at is your exhaust down pipes for interference marks, its possible one of them either came loose (they have a bracket that connects in that area) or the bracket is broke.

Thanks. Those are two things I haven't checked. I'll have to check where the subframe hardware is


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[JayDog747]

Have you checked/ re-torqued your subframe hardware? Also something to look at is your exhaust down pipes for interference marks, its possible one of them either came loose (they have a bracket that connects in that area) or the bracket is broke.

While you're down there, inspect the heat shields also. If after you re-torque the sub frame bolt and it still persist, consider replacing the bolt.

[alcatranz518]

I wanted to add to my original post and apparently forgot this small but important point.

The "clunk" I would hear with bumps was much more minimal if anything nonexistent if the brake were applied over these said bumps that under usual conditions would cause the "clunking" noise. That was the trigger to my hypothesis of the pad bushings being the culprit.

*NOTE*: The "clunk" noise is not to be confused with the usual "clank" from a weak pad spring upon pressing on the brake pedal that I also had and was differentiated with my experiments on the road I was using for the tests.

[gautam]

I wanted to add to my original post and apparently forgot this small but important point.

The "clunk" I would hear with bumps was much more minimal if anything nonexistent if the brake were applied over these said bumps that under usual conditions would cause the "clunking" noise. That was the trigger to my hypothesis of the pad bushings being the culprit.

*NOTE*: The "clunk" noise is not to be confused with the usual "clank" from a weak pad spring upon pressing on the brake pedal that I also had and was differentiated with my experiments on the road I was using for the tests.

Holy shit this has been bugging me for a whole year now! I replaced the brake discs with large diameter vented slotted ones and new RedStuff performance brake pads, and ever since then I've been getting the clunking noise you described. I thought it was something in the suspension so I changed out all 8 control arms (the ball joint bushings were shot anyways) to no avail. Looked at the snub mount because I thought it was moving around inside the bracket and it doesn't look good either so I'll be changing it anyways, but I wasn't sure if it would remedy the problem with the god damn clunking.

Went over the same bumps I go over with the brakes slightly engaged and VOILA little to no clunking noise!! Gonna set about installing the ECS kit soon.

[alcatranz518]

SWEET! I am hopeful this helps fix yours and many of the other members' front end noise gremlin.

As Jay said earlier, and I have seen there can be other causes that should be checked (even for safety reasons)...such as the sub-frame hardware, wheel bearing mounting hardware, or the rack and pinion mount hardware needing re-torqued (this platform reminds me so much of race car/ bikes needing much of the hardware loctited and re-torqued periodically after so many miles).

Again, because the one signal trait for me on this was the applying the brakes over bumps that reduced eliminated the noise, that's what led me to mine that I didn't read others tried. I really hope this helps many of you.

[FastEddie]

Holy shit this has been bugging me for a whole year now! I replaced the brake discs with large diameter vented slotted ones and new RedStuff performance brake pads, and ever since then I've been getting the clunking noise you described. I thought it was something in the suspension so I changed out all 8 control arms (the ball joint bushings were shot anyways) to no avail. Looked at the snub mount because I thought it was moving around inside the bracket and it doesn't look good either so I'll be changing it anyways, but I wasn't sure if it would remedy the problem with the god damn clunking.

Went over the same bumps I go over with the brakes slightly engaged and VOILA little to no clunking noise!! Gonna set about installing the ECS kit soon.

Its Tyrolsport's kit, ECS just sells it. I bring my car to Tyrol for all my work (they are local). AMAZING SHOP!!!

[Salvaje]

Anyone have any other suggestions? I've tried everything so far. Subframe bolts, upper and lower control arms, shock mount bushing, steering bolts, everything has been torn apart many times. Seems like I can feel it most of the time. Right in front of my gas pedal. D Irving down my bumpy road without brakes on and under acceleration and deceleration.
Oh and I've done engine mounts and snub mount. It's a triptronic. I bought the car with 82,000 miles and it did it a little then and now maybe a little worse. No play in the steering rack


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[alcatranz518]

What kind of sway bar bushings do you have on it (or have they been replaced)? Have you checked that the hardware for the brackets are still secure? The bushings that mount the bar when bad can "appear" to be good, but cause a front end noise like you describe from the bar rattling around in bumps. Because of the strength of the bar, its hard to notice or simulate and near impossible under visual inspection to see they have worn out (unless under extreme failures that they just came apart).

Also, do you have a larger front sway bar and if so did you upgrade the end links? An educated guess I'll make is that upgraded front bars will wipe out the OEM end links, even the "upgraded" links won't last. The spherical end links are basically the only reliable option for the front bar upgrade. Even the 034 rubber upgrades don't last (they do last longer, but still will wear out within about a year-depending on how much "spirited driving" you do).

[Salvaje]

What kind of sway bar bushings do you have on it (or have they been replaced)? Have you checked that the hardware for the brackets are still secure? The bushings that mount the bar when bad can "appear" to be good, but cause a front end noise like you describe from the bar rattling around in bumps. Because of the strength of the bar, its hard to notice or simulate and near impossible under visual inspection to see they have worn out (unless under extreme failures that they just came apart).

Also, do you have a larger front sway bar and if so did you upgrade the end links? An educated guess I'll make is that upgraded front bars will wipe out the OEM end links, even the "upgraded" links won't last. The spherical end links are basically the only reliable option for the front bar upgrade. Even the 034 rubber upgrades don't last (they do last longer, but still will wear out within about a year-depending on how much "spirited driving" you do).

Front sway bar is stock and the bushings look ok. I actually loosened the brackets to see if it made a difference.
I am gonna try the caliper fix also. Think it's a far shot but all it can do is help.


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