[BabyM240i]

Anyone else have recurring experiences with pebbles getting stuck in the brakes? Three times now, since picking the car up in December, I’ve had pebbles get stuck between the heat shield and back of the rotor. HOLY SHIT the sound. Loud like people across parking lots stairring at me.

Only once I’ve actually retrieved the pebble by wiggling the shield. The two other times I had to drive it out. Has anyone else experienced this? Can I be sure it is pebbles? I don’t exactly drive down gravel roads so I’m not entirely sure why I’m experiencing this so much with this car. My Hyundai with over 100k miles never had it happen. Thoughts?

[JoeyJoeJo]

I've had it and the sound is truly awful, there must be some specific resonance in the setup. It didn't shift after a couple of emergency stop hard braking so BMW came out and removed it, techs said it's surprisingly common. Luckily only quarter a mile from home, was literally screaming.

[RockCrusher]

Originally Posted by BabyM240i

Anyone else have recurring experiences with pebbles getting stuck in the brakes? Three times now, since picking the car up in December, I’ve had pebbles get stuck between the heat shield and back of the rotor. HOLY SHIT the sound. Loud like people across parking lots stairring at me.

Only once I’ve actually retrieved the pebble by wiggling the shield. The two other times I had to drive it out. Has anyone else experienced this? Can I be sure it is pebbles? I don’t exactly drive down gravel roads so I’m not entirely sure why I’m experiencing this so much with this car. My Hyundai with over 100k miles never had it happen. Thoughts?

First encountered this with my Porsche Boxster. Once when driving on a city street littered with twigs -- the result of an ice storm -- managed to get a twig caught between the rotor and splash shield.

Reversing the car and while backing up turning the steering wheel full lock to lock dislodged the twig.

Second time when backing out of a parking space at the office what proved to be a tiny sharp rock dropped off the tire and down in between the rotor and splash shield. Thought the noise the twig made was bad... Oh my this was 10 times worse.

Long story short had to jack up the right front corner of the car remove the wheel and pry the splash shield away from the rotor a bit and the rock fell out.

More recently my 230ix managed to get a something -- probably a small rock/pebble -- caught in the brakes of one front wheel. Fortunately whatever it was fell out a couple of moments later before I felt it necessary to try to dislodge the item.

This appears to arise due to the wide front tires and when turned at close to or at full lock that the inside wheel/tire is canted over with the brake rotor/splash shield exposed to any trash that falls off the tread of the tire.

Haven't bothered to take a pic of either my 230ix or M2 but a pic of my Boxster's front tires turned full lock is attached.

While the brake rotor/splash shield is not visible -- hidden in the shadow -- it is clear it is at risk of any debris that might fall off the tire as it rotates.

[apez]

Has happened toe as well. 2 or 3 times in the same day at an autocross event. Backing up while wiggling the steering worked in all cases

I wonder if it could be spacer related that the inner edge of the tire is pushed too far out making it easy for stuff to drop in.

[BabyM240i]

Originally Posted by apez

Has happened toe as well. 2 or 3 times in the same day at an autocross event. Backing up while wiggling the steering worked in all cases

I wonder if it could be spacer related that the inner edge of the tire is pushed too far out making it easy for stuff to drop in.

I do have more open or exposed, wider wheels… spacers, sticky tires, and dirty streets due to fiber install. Perhaps there is something to your theory!

Crazy, never ever had this happen. Had a GTO, GTO, Jeep, and several other cars. On and off road. And now I seemingly can’t get down my road own street 😂

It’s unbelievably, alarmingly, loud!

[BabyM240i]

Originally Posted by RockCrusher

First encountered this with my Porsche Boxster. Once when driving on a city street littered with twigs — the result of an ice storm — managed to get a twig caught between the rotor and splash shield.

Reversing the car and while backing up turning the steering wheel full lock to lock dislodged the twig.

Second time when backing out of a parking space at the office what proved to be a tiny sharp rock dropped off the tire and down in between the rotor and splash shield. Thought the noise the twig made was bad... Oh my this was 10 times worse.

Long story short had to jack up the right front corner of the car remove the wheel and pry the splash shield away from the rotor a bit and the rock fell out.

More recently my 230ix managed to get a something — probably a small rock/pebble — caught in the brakes of one front wheel. Fortunately whatever it was fell out a couple of moments later before I felt it necessary to try to dislodge the item.

This appears to arise due to the wide front tires and when turned at close to or at full lock that the inside wheel/tire is canted over with the brake rotor/splash shield exposed to any trash that falls off the tread of the tire.

Haven't bothered to take a pic of either my 230ix or M2 but a pic of my Boxster's front tires turned full lock is attached.

While the brake rotor/splash shield is not visible — hidden in the shadow — it is clear it is at risk of any debris that might fall off the tire as it rotates.

Is your user name related? lol

[Navin_Johnson]

Originally Posted by apez

Has happened toe as well. 2 or 3 times in the same day at an autocross event. Backing up while wiggling the steering worked in all cases

I wonder if it could be spacer related that the inner edge of the tire is pushed too far out making it easy for stuff to drop in.

That's a great point! Others who have had this happen should chime in with if they have any spacers between their wheels and the hub.
Having had many cars, and done many brake jobs, I seem to recall most cars had the top of the dust shield rolled over towards the wheel, sort of adding material to cover the gap between the shield and the back of the rotor. When I had my wheels off the other day, I didn't notice the shape of the shield. If it doesn't roll over at all, it very well could leave a space for pebbles to fall into.

[lachyn]

Happened to me last week. I have stock M240i with ZTK. I didn't hear it at first because I had the radio on loud and the windows rolled up, and I wondered why everyone was staring at me. After the song stopped playing, I immediately realized why. I stopped and, as already said, by moving back and forth on the spot and turning the steering wheel, the stone came loose.

[Pentland]

Originally Posted by Navin_Johnson

That's a great point! Others who have had this happen should chime in with if they have any spacers between their wheels and the hub.
Having had many cars, and done many brake jobs, I seem to recall most cars had the top of the dust shield rolled over towards the wheel, sort of adding material to cover the gap between the shield and the back of the rotor. When I had my wheels off the other day, I didn't notice the shape of the shield. If it doesn't roll over at all, it very well could leave a space for pebbles to fall into.

Only happened to me once on the M240i. At the time, no spacers (ZKT kit)

[BabyM240i]

Originally Posted by Pentland

Only happened to me once on the M240i. At the time, no spacers (ZKT kit)

ZTK seems to be common 🤔

[Littlecoupe]

I had it happen once on track (and no, I did not drive into a gravel pit). I have not noticed it happening since. I was able to wiggle the shield and dislodge the stone. I am on 893m (ZTK) wheels, but not the ZTK package for brakes and cooling.

I work with someone who owns a FK8 Civic Type R, he mentioned the CTR likes to lodge rocks between the caliper/shield and rotor. Seems to be a performance car issue. All the various factors coming together, and maybe the large multi-piston brakes play a role.

[Pentland]

Originally Posted by Pentland

Only happened to me once on the M240i. At the time, no spacers (ZKT kit)

You guys are a curse.

A stone stuck in between the heat shield and disc in the front nearside today. Picked up as i pulled out of a parking space.
Took the wheel off to prise it out.