[CartwheelingTheVoid]

Hi, everyone!

As the title suggests, I'm trying to diagnose a clunking sound, coming from driver's side front axle. The car is a 2012 i30 1.6 CW with slightly over 100 000 kms on it. It started a couple of months ago as a vague, intermittent metallic clunk. I thought the problem might be bad anti sway bar links in the front, so I replaced them. Everything seemed fine, but about one week ago the clunking came back with a vengeance. Not sure if it's actually the same issue, but regardless, this is what I've gathered so far:

- The clunking is quite metallic, thumping and rotational, increasing/decreasing linearly with the speed of the car. It's not there if the car's going below 20 km/h or so.
- It's intermittent. Sometimes it's loud, sometimes it's barely discernible, and sometimes it's not there. No obvious pattern.
- It's not affected by bumps or unevenness in the road.
- It doesn't seem to affect the performance of the car in any way.
- It's not coming from the engine. If I turn the engine off, it doesn't affect the clunking.
- It's hard to provoke. Turning the steering wheel slightly to the left can make it louder, but not consistently. Doing the standard test of the outer CV joints, driving the car in reverse with the steering wheel fully turned in both directions, does not cause the sound to appear.
- Accelerating can make the sound slightly louder, but it does not disappear when you decelerate. 
- However, touching the brakes ever so softly will cause the clunking to stop completely, consistently.

And yes, I do have recordings of it! Both of these clips have been recorded while driving the car in a straight line at constant speeds of ~40 and 60 km/h.

Recording_72
Recording_73

Any input would be appreciated! I'm thinking it's either the outer or inner CV joint, but some of the symptoms (like the brakes killing the clunking) puzzles me.

[The Gonz]

Your mention of the brakes has me thinking loose pads.

[CartwheelingTheVoid]

Excellent, I'll start there this weekend and see if I can find anything. Thank you! The thought also struck me, maybe it's a caliper piston that's partly stuck?

[sundiz]

Better check brakes as Gonz said. One possibility could be hub bearing, as it can change the alingment when brakes are pushed. But I would start with the brake check.

Not sure if your car has ball joint covers. I had my bent at some point and started making noise, but it was more grinding than clunking. It made contact to brake disk under load when turning harsly.