[Sail Boat]

Welcome back to yet another thread about my front-end clunk-solving adventure! Slowly but surely, the knock/clunk/bangs have returned. It is driving me up a gosh darn wall, it makes me want to put this car in timeout.

The front end clunk has been discussed at great length, but I don't think this is a universal issue. The two main culprits are EDC valving (reprogrammable) and steering racks. Interestingly, despite these "fixes" the noise seems to reappear over time.

Check out below and let me know if you all find anything I'm missing - I'm about ready to just purchase all new suspension components and try from scratch.

The noise:
happens when one wheel suddenly changes in vertical direction, up or down, in relation to the other wheel. For instance driving over a crack in the road, manhole, small pothole, or even a bump.

What I've done:
1) Removed the EDC system entirely by installing KW V3 coilovers, ruling out the EDC problem. No noise for 500 miles or so, then returned.
2) Disconnected the steering rack tie rods, checked for play. None was found, ruling out the steering rack.
3) Tried shorter, OEM, and Longer end links. Each worked for a period of time but knocking returned.
4) Checked Thrust arm and LCA, both seem fine.
5) Checked to make sure the tophats are bolted down and shaft is torqued properly.

One thing I am trying again is disconnecting the front sway bar. I'll drive around for a while to see if it makes a difference. When I did this in the past, it seemed to solve the issue entirely... Of course after discovering this, I was 100% certain that the knocking was coming from the swaybar "walking" due to worn out bushings. This makes sense because it is the only suspension component tying together vertical motion on both wheels.

I also have a suspicion that it is the tophats. Realoem indicates that the tophats for EDC vs. Non-EDC cars are different, but I can't imagine the two parts are that much different. Could this be the problem?

[opvaulet]

I had a similar problem. Turned out to be the TOP mounts. Clonking disappeared after I replaced them.

[Joaco135]

Interested in findings since have the same clunk problem.....

[XutvJet]

When the clunking began to occur, had the car already been lowered on springs prior to the coilovers? From what I've learned over the years on this site is that the top hats do not take kindly to lowering, especially anything over 1/2 inch as it increases camber and puts stress on the top hat bearing. The hats are designed for the OEM camber settings and anything that changes camber can apparently put them at an operating angle/stroke that car wear them out and/or cause clunking. The top hats in the F series BMWs are quite a bit different in design compared to most other makes and the tolerances are much tighter.

I've had prior cars where I've gotten similar clunking in the front. All were lowered and when I thought the issue was resolved, it reappeared after 50-100 miles. The culprit was the top hat. Either it was worn out or the strut nut wasn't torque to spec.

[EVEda235i]

Great write up! Srry to hear it's evading you. I would check the tie rods again. Mine were bowed out at a very low mileage. Its esier to notice any bowing when adjusting them during an alignment. Same thing happened to my friends m235i. Good luck

[opvaulet]

Originally Posted by opvaulet

I had a similar problem. Turned out to be the TOP mounts. Clonking disappeared after I replaced them.

I had the noise on stock springs. Upgraded to Eibach pro kit noise was still there. Originally quite faint it got louder over the miles.

[Sail Boat]

Inspired by XutvJet's tophat (or top mount) theory, I dropped Vorshlag a line and they confirmed that the noise, from their experience, does indeed originate from the tophats and not from the swaybar walking. They also confirmed that the steering rack issue is an entirely different problem related to steering inputs at low speeds/stationary, not to be confused with brake pads tapping against rotors. Regardless I'll check that the rods are straight.

After this news, I called by local BMW shop who also confirmed that this is usually the problem - in fact, it apparently happens on some F30/F8X cars as well. According to them, the clunk/chatter noise is entirely eliminated from every car post coilover/vorshlag plate install.

I'll give it a shot and report back.

[arhoads335i]

Does it sound like it comes from the front driver side wheel? If so probably power steering rack

[_M228i]

Check the end links bro, I took my wheel off and thought I looked thoroughly for any thing loose. And two weeks later (today) I decided to reach through the wheel and feel my end links, sure enough I felt threads on the upper part of the end link. Ill try to get pics when I take the wheel off again. I should've upgraded before this happened

[dradernh]

Originally Posted by _M228i

Check the end links bro, I took my wheel off and thought I looked thoroughly for any thing loose. And two weeks later (today) I decided to reach through the wheel and feel my end links, sure enough I felt threads on the upper part of the end link. Ill try to get pics when I take the wheel off again. I should've upgraded before this happened

https://www.2addicts.com/forums/show...56&postcount=1

[_M228i]

Originally Posted by dradernh

https://www.2addicts.com/forums/show...56&postcount=1

Wow, no wayy

[dradernh]

Originally Posted by _M228i

Wow, no wayy

I know, right – it seems that, sooner or later, everyone does it. Go figure.