Brakes Making Vibrations and Weird Noises

[Powerslide]

Originally Posted by jritt@essex

It sounds like you may possibly have uneven pad deposits on your discs. As described above...at some point when the brakes were hot, some pad material got stuck to the face of the disc. That pad material creates a high spot, and every time the disc spins past the caliper the pad hits that hump on the disc causing a vibration. The only potential solution if that is the problem is to scrub the disc and start over with a fresh bed-in procedure.

That said, if the noise is really that sever and causing an actual grinding noise (not vibration) in the cabin, it could be something different. Have you actually pulled the pads out and inspected them? Believe it or not, sometimes debris gets caught in a caliper (small rocks, etc.), and can make a mess of things.

These issues are tough to diagnose without actually seeing the car. Describing noises is always tricky!

If you do want to try a different set of pads, we have a great Ferodo compound that is perfect for the street/autoX...DS2500. We have it front and rear for the F80.

Front

Rear

So - with the stock pads - can regular (not spirited) street use cause the stock pads to reach a high enough temperature where pad material can transfer to the pads for an ordinary stop at a traffic light? I was always under the impression that one could only generate sufficiently high temperatures from track use for this to be a concern (which is why people run "cool down" laps for the brakes after tracking or high-speed autocrossing - I've never heard of a need for "cool down" or special precautions to be taken when driving in ordinary traffic).

Like others in this thread - I've had cross-drilled rotors on other cars and never had this problem - and I also bedded the pads exactly as the owner's manual said for the first 300+ miles - but still get that vibration through the steering wheel...

Any further suggestions, theories or advice are welcome!

[hdubf80]

Originally Posted by Powerslide

So - with the stock pads - can regular (not spirited) street use cause the stock pads to reach a high enough temperature where pad material can transfer to the pads for an ordinary stop at a traffic light? I was always under the impression that one could only generate sufficiently high temperatures from track use for this to be a concern (which is why people run "cool down" laps for the brakes after tracking or high-speed autocrossing - I've never heard of a need for "cool down" or special precautions to be taken when driving in ordinary traffic).

Like others in this thread - I've had cross-drilled rotors on other cars and never had this problem - and I also bedded the pads exactly as the owner's manual said for the first 300+ miles - but still get that vibration through the steering wheel...

Any further suggestions, theories or advice are welcome!

Theres no good reason why the brakes on a new 85k performance vehicle should be doing this IMO. BMW needs to offer a fix...

[Powerslide]

Originally Posted by hdubf80

Theres no good reason why the brakes on a new 85k performance vehicle should be doing this IMO. BMW needs to offer a fix...

Totally agree - steering wheel should not vibrate most times when decelerating above 40 mph when driving in traffic and decelerating at same rate as non-performance cars - this is the only aspect of the F8x that I am disappointed with.

[Powerslide]

I should also add that I previously had a 4,150 lb. E93 - which supposedly had less capable brakes and 500 lbs. more weight to bring to a stop vs.my F8x - yet not once in 80,000 miles did I have this issue with my E93...

[hdubf80]

Originally Posted by Powerslide

I should also add that I previously had a 4,150 lb. E93 - which supposedly had less capable brakes and 500 lbs. more weight to bring to a stop vs.my F8x - yet not once in 80,000 miles did I have this issue with my E93...

IKR. Still waiting for a fix

[Powerslide]

Bringing mine in to the dealer on Monday - I'll post the results when the car is done...

[Grayf82]

Took my car in for groaning brakes. Dealer said everything is OK. It is not. I think the only soloution is to go aftermarket pads with higher heat capacity. Tech confirmed a new car on the lot did it too.

[Powerslide]

Originally Posted by gmsracing

Took my car in for groaning brakes. Dealer said everything is OK. It is not. I think the only soloution is to go aftermarket pads with higher heat capacity. Tech confirmed a new car on the lot did it too.

Did you also feel vibration in the brake pedal and steering wheel?

[hdubf80]

Originally Posted by Powerslide

Bringing mine in to the dealer on Monday - I'll post the results when the car is done...

Please let me know what they say... If you figure out the solution ill have to send you a gift basket or something. Shit is driving me insane...

Originally Posted by gmsracing

Took my car in for groaning brakes. Dealer said everything is OK. It is not. I think the only soloution is to go aftermarket pads with higher heat capacity. Tech confirmed a new car on the lot did it too.

What pads do you recommend?

[Powerslide]

[QUOTE=hdubf80;19435371]Please let me know what they say... If you figure out the solution ill have to send you a gift basket or something. Shit is driving me insane...


So - I took my car out for a drive late last night (no traffic out). I did some fairly aggressive stops, first from 40mph down to about 15-20 mph (never coming to complete stop), then some from about 60-65 mph down to about 35-40 mph. The amount of force I used was not quite enough to trigger the ABS - so imagine almost maximum decelerative force short of ABS. I would do maybe 2-3 such stops in fairly short succession, then let the brakes cool for a few minutes (while driving at about 40-60 mph in 35 F weather).

I noticed that the brakes got smoother as the drive went on. Now granted, there is still some "groan" sound, and still just a little bit of vibration above 40 mph, but in some instances, it was much lighter than before, and in a few instances, barely even noticeable (whereas on Saturday, it was vibrating so much in the steering wheel and brake pedal I thought I was driving a jackhammer)!!

So - I elected not to go through the time-consuming venture of going to the dealership (about 25-30 minutes from home, and not on the way to work), taking the time to go back and exchange the loaner for my car, etc. etc.

What I am going to do is see how the car does in the next few weeks - I starting to think that what may have happened in my case (and possibly others' cases as well, including yours) is one or both of the following:

1) somehow I got pad deposit unevenly distributed on the rotors; and/or

2) I needed to "burn off" the pad deposit by being more aggressive and applying more brake pedal force when decelerating.

It is still too early to know if either 1) or 2) were in play, but last night's results were somewhat encouraging. Will keep you posted on this thread. You may want to try something similar to what I did last night and see if you notice an improvement.

[bradleym]

[QUOTE=Powerslide;19436211]

Originally Posted by hdubf80

Please let me know what they say... If you figure out the solution ill have to send you a gift basket or something. Shit is driving me insane...


So - I took my car out for a drive late last night (no traffic out). I did some fairly aggressive stops, first from 40mph down to about 15-20 mph (never coming to complete stop), then some from about 60-65 mph down to about 35-40 mph. The amount of force I used was not quite enough to trigger the ABS - so imagine almost maximum decelerative force short of ABS. I would do maybe 2-3 such stops in fairly short succession, then let the brakes cool for a few minutes (while driving at about 40-60 mph in 35 F weather).

I noticed that the brakes got smoother as the drive went on. Now granted, there is still some "groan" sound, and still just a little bit of vibration above 40 mph, but in some instances, it was much lighter than before, and in a few instances, barely even noticeable (whereas on Saturday, it was vibrating so much in the steering wheel and brake pedal I thought I was driving a jackhammer)!!

So - I elected not to go through the time-consuming venture of going to the dealership (about 25-30 minutes from home, and not on the way to work), taking the time to go back and exchange the loaner for my car, etc. etc.

What I am going to do is see how the car does in the next few weeks - I starting to think that what may have happened in my case (and possibly others' cases as well, including yours) is one or both of the following:

1) somehow I got pad deposit unevenly distributed on the rotors; and/or

2) I needed to "burn off" the pad deposit by being more aggressive and applying more brake pedal force when decelerating.

It is still too early to know if either 1) or 2) were in play, but last night's results were somewhat encouraging. Will keep you posted on this thread. You may want to try something similar to what I did last night and see if you notice an improvement.

if you got pad deposits on the rotors, then likely this will come back. when i had this problem on another car, the issue would come and go--i frequently did what you described above, thinking i could clean them off. the only way i made the issue go away completely was to replace both pads and rotors, then was very careful about the break-in. that particular car has been vibration free for two years now, so i think it is safe to say it is resolved.

[FLOSS M]

My previous e90/e92M3 didn't have this problem. I notice the same noise and vibration as mentioned above on my M4 under hard braking.

[Powerslide]

[QUOTE=bradleym]

Originally Posted by Powerslide

if you got pad deposits on the rotors, then likely this will come back. when i had this problem on another car, the issue would come and go--i frequently did what you described above, thinking i could clean them off. the only way i made the issue go away completely was to replace both pads and rotors, then was very careful about the break-in. that particular car has been vibration free for two years now, so i think it is safe to say it is resolved.

I've already had the pads and rotors replaced under warranty - I was very meticulous about breaking in the pads/rotors per the owner's manual for 300+ miles - everything fine for first 1000-2000 miles - then the vibration/judder started coming back again - so -pads and rotors only have 3000 miles on them - and this issue has already returned.

Also never had this problem on my E93 - 80,000 miles on that one!!

[mc3456]

Originally Posted by SakhirM4

Don't have that problem with my M4, so they don't all do it.

Mine does it sporadically but only under hard braking. May be unnerving to some people, but as long as there is no loss of braking power, I'm not bothered by it.

[Powerslide]

[QUOTE=Powerslide;19436211]

Originally Posted by hdubf80

Please let me know what they say... If you figure out the solution ill have to send you a gift basket or something. Shit is driving me insane...


So - I took my car out for a drive late last night (no traffic out). I did some fairly aggressive stops, first from 40mph down to about 15-20 mph (never coming to complete stop), then some from about 60-65 mph down to about 35-40 mph. The amount of force I used was not quite enough to trigger the ABS - so imagine almost maximum decelerative force short of ABS. I would do maybe 2-3 such stops in fairly short succession, then let the brakes cool for a few minutes (while driving at about 40-60 mph in 35 F weather).

I noticed that the brakes got smoother as the drive went on. Now granted, there is still some "groan" sound, and still just a little bit of vibration above 40 mph, but in some instances, it was much lighter than before, and in a few instances, barely even noticeable (whereas on Saturday, it was vibrating so much in the steering wheel and brake pedal I thought I was driving a jackhammer)!!

So - I elected not to go through the time-consuming venture of going to the dealership (about 25-30 minutes from home, and not on the way to work), taking the time to go back and exchange the loaner for my car, etc. etc.

What I am going to do is see how the car does in the next few weeks - I starting to think that what may have happened in my case (and possibly others' cases as well, including yours) is one or both of the following:

1) somehow I got pad deposit unevenly distributed on the rotors; and/or

2) I needed to "burn off" the pad deposit by being more aggressive and applying more brake pedal force when decelerating.

It is still too early to know if either 1) or 2) were in play, but last night's results were somewhat encouraging. Will keep you posted on this thread. You may want to try something similar to what I did last night and see if you notice an improvement.

So - one thing I've noticed is that the brake judder seems worse after a car wash - it was pretty bad last Saturday - got better last Sunday night and then today - after a car wash - it was worse again...

Tried to do same thing as in my quoted post above again this afternoon - and brake judder still bad...especially while decelerating below 50-60 mph and above 40 mph...

I think I'm going to have to take the car in again - this is so massively frustrating. I've never had a car that brake judders like this one - despite breaking in the brakes per the owner's manual and being careful not to leave the brake pedal pushed down at a stop when the brakes are at higher temps.

[hdubf80]

[QUOTE=Powerslide;19471732]

Originally Posted by Powerslide

So - one thing I've noticed is that the brake judder seems worse after a car wash - it was pretty bad last Saturday - got better last Sunday night and then today - after a car wash - it was worse again...

Tried to do same thing as in my quoted post above again this afternoon - and brake judder still bad...especially while decelerating below 50-60 mph and above 40 mph...

I think I'm going to have to take the car in again - this is so massively frustrating. I've never had a car that brake judders like this one - despite breaking in the brakes per the owner's manual and being careful not to leave the brake pedal pushed down at a stop when the brakes are at higher temps.

I feel your pain. This issue has to be addressed by BMW. I'm pretty sure if we make enough noise they can offer us a fix or something. Maybe performance parts lol. This was the first New car I've bought My previous ///M was used and I never had the problem there. I feel like I've been ripped off if that makes sense.

[Powerslide]

[QUOTE=hdubf80;19471896]

Originally Posted by Powerslide

I feel your pain. This issue has to be addressed by BMW. I'm pretty sure if we make enough noise they can offer us a fix or something. Maybe performance parts lol. This was the first New car I've bought My previous ///M was used and I never had the problem there. I feel like I've been ripped off if that makes sense.

I do too - no way a car this expensive with a Motorsports pedigree should be doing this... especially after got all new front and rear brake pads and rotors only 3,000 miles ago (no tracking during that time). Unbelieveable...

[jritt@essex]

Argh...sorry you guys are going through this hassle!

Normally under daily driving situations, you would not be getting the pads hot enough to make a major deposit on the disc (unless the OE pads has a seriously low max operating temp...which I doubt). If you went out on country roads/canyons and were blasting around, it would be very easy to get the pads hot enough to stick to the disc.

There's no reason to believe a car wash would have any impact on brake performance. When they get wet your discs will form a little surface rust, but that is swept off as soon as you apply your brakes the first time.

The fact that Powerslide's issues abated after getting hard on the brakes a bit leads me to believe that it is indeed an issue with the interface of the pad and disc. Chasing uneven pad deposits can be a royal pain for sure. Have you guys ever seen my video on swapping between street and track pads? Scroll down on that page to see it. The easiest way to scrub discs is with aggressive racing pads. They have a higher mu, and when cold, they can clean up a disc face rather quickly.

Has anyone with this groaning noise down a proper full pad/disc bed-in? By proper I don't mean a few hard stops scrubbing a span of 15-20mph. I'm talking about blasting them hard enough to get the pads actually smoking. To do that you need to go from 60mph+ down to 5mph. If you don't you won't get enough heat into the pads to make them stick to the discs. Please see my video in the link above on that topic...braking repeatedly hard enough to really get the pads seated on the discs, and get a solid amount of material transferred onto the disc face. If the pads and discs aren't bed-in, you're going to have more noise, chatter, etc. of the pad on the drill holes or slots, and also more potential groaning of the pad on the iron disc face.

Think of it this way...the pad and disc are two different hunks of differing metal. You're rubbing them together. When you do that, you're going to get some noise. The surfaces of those two items are going to be imperfectly mated, since each has its own irregularities. The bedding process is used to mate those surfaces together and eliminate those irregularities, and that is done through force and heat.

Again, as long as the caliper bolts holding it to the spindle are tight, and the disc is running centered in the caliper, there's not a lot other potential culprits other than the pad and disc interface.

As for disc noise with drill holes and slots...that is a valid possibility. It doesn't happen on all cars, but we do see it on some. In the hierarchy of noise, from quietest to noisiest would be plain face, straight slot, J Hook Slot, Drill holes. The noise you get from holes or slots is typically not a groaning...it is more of a scraping or whirring noise. You would hear it when you drive next to a wall and the sound bounces off the wall and back to you.

The fact that the issues are speed-dependent are really odd. Normally with a pad deposit you will feel it most of the time, and it tends to be more severe/violent the harder you're stopping.

The only way you guys are going to isolate the issue is to change one thing at a time on the car.
1. Change the brake pads out to something non-oem and leave everything else alone...check for noise.
2. If still present, put on fresh discs and check again.
3. If you change out the pads and discs and the noise is still present, you have something else going on.

Anybody with this problem live around Charlotte, NC? If so, we'd be happy to look at the car and see if we can isolate the issue and its cause. My gut tells me that a proper bed-in will take care of this issue. A proper bed-in is typically more aggressive than what people do. Most people back off too early, aren't braking hard enough, aren't scrubbing enough speed, etc. Watch my videos...they show exactly what I'm talking about better than I can write it. Thanks.

[Powerslide]

Originally Posted by jritt@essex

Argh...sorry you guys are going through this hassle!

Normally under daily driving situations, you would not be getting the pads hot enough to make a major deposit on the disc (unless the OE pads has a seriously low max operating temp...which I doubt). If you went out on country roads/canyons and were blasting around, it would be very easy to get the pads hot enough to stick to the disc.

There's no reason to believe a car wash would have any impact on brake performance. When they get wet your discs will form a little surface rust, but that is swept off as soon as you apply your brakes the first time.

The fact that Powerslide's issues abated after getting hard on the brakes a bit leads me to believe that it is indeed an issue with the interface of the pad and disc. Chasing uneven pad deposits can be a royal pain for sure. Have you guys ever seen my video on swapping between street and track pads? Scroll down on that page to see it. The easiest way to scrub discs is with aggressive racing pads. They have a higher mu, and when cold, they can clean up a disc face rather quickly.

Has anyone with this groaning noise down a proper full pad/disc bed-in? By proper I don't mean a few hard stops scrubbing a span of 15-20mph. I'm talking about blasting them hard enough to get the pads actually smoking. To do that you need to go from 60mph+ down to 5mph. If you don't you won't get enough heat into the pads to make them stick to the discs. Please see my video in the link above on that topic...braking repeatedly hard enough to really get the pads seated on the discs, and get a solid amount of material transferred onto the disc face. If the pads and discs aren't bed-in, you're going to have more noise, chatter, etc. of the pad on the drill holes or slots, and also more potential groaning of the pad on the iron disc face.

Think of it this way...the pad and disc are two different hunks of differing metal. You're rubbing them together. When you do that, you're going to get some noise. The surfaces of those two items are going to be imperfectly mated, since each has its own irregularities. The bedding process is used to mate those surfaces together and eliminate those irregularities, and that is done through force and heat.

Again, as long as the caliper bolts holding it to the spindle are tight, and the disc is running centered in the caliper, there's not a lot other potential culprits other than the pad and disc interface.

As for disc noise with drill holes and slots...that is a valid possibility. It doesn't happen on all cars, but we do see it on some. In the hierarchy of noise, from quietest to noisiest would be plain face, straight slot, J Hook Slot, Drill holes. The noise you get from holes or slots is typically not a groaning...it is more of a scraping or whirring noise. You would hear it when you drive next to a wall and the sound bounces off the wall and back to you.

The fact that the issues are speed-dependent are really odd. Normally with a pad deposit you will feel it most of the time, and it tends to be more severe/violent the harder you're stopping.

The only way you guys are going to isolate the issue is to change one thing at a time on the car.
1. Change the brake pads out to something non-oem and leave everything else alone...check for noise.
2. If still present, put on fresh discs and check again.
3. If you change out the pads and discs and the noise is still present, you have something else going on.

Anybody with this problem live around Charlotte, NC? If so, we'd be happy to look at the car and see if we can isolate the issue and its cause. My gut tells me that a proper bed-in will take care of this issue. A proper bed-in is typically more aggressive than what people do. Most people back off too early, aren't braking hard enough, aren't scrubbing enough speed, etc. Watch my videos...they show exactly what I'm talking about better than I can write it. Thanks.

Thanks for taking the time to write that excellent reply and advice - definitely appreciate that! I'll keep updating this thread as I learn more or as developments continue...

[hdubf80]

Originally Posted by jritt@essex

Argh...sorry you guys are going through this hassle!

Normally under daily driving situations, you would not be getting the pads hot enough to make a major deposit on the disc (unless the OE pads has a seriously low max operating temp...which I doubt). If you went out on country roads/canyons and were blasting around, it would be very easy to get the pads hot enough to stick to the disc.

There's no reason to believe a car wash would have any impact on brake performance. When they get wet your discs will form a little surface rust, but that is swept off as soon as you apply your brakes the first time.

The fact that Powerslide's issues abated after getting hard on the brakes a bit leads me to believe that it is indeed an issue with the interface of the pad and disc. Chasing uneven pad deposits can be a royal pain for sure. Have you guys ever seen my video on swapping between street and track pads? Scroll down on that page to see it. The easiest way to scrub discs is with aggressive racing pads. They have a higher mu, and when cold, they can clean up a disc face rather quickly.

Has anyone with this groaning noise down a proper full pad/disc bed-in? By proper I don't mean a few hard stops scrubbing a span of 15-20mph. I'm talking about blasting them hard enough to get the pads actually smoking. To do that you need to go from 60mph+ down to 5mph. If you don't you won't get enough heat into the pads to make them stick to the discs. Please see my video in the link above on that topic...braking repeatedly hard enough to really get the pads seated on the discs, and get a solid amount of material transferred onto the disc face. If the pads and discs aren't bed-in, you're going to have more noise, chatter, etc. of the pad on the drill holes or slots, and also more potential groaning of the pad on the iron disc face.

Think of it this way...the pad and disc are two different hunks of differing metal. You're rubbing them together. When you do that, you're going to get some noise. The surfaces of those two items are going to be imperfectly mated, since each has its own irregularities. The bedding process is used to mate those surfaces together and eliminate those irregularities, and that is done through force and heat.

Again, as long as the caliper bolts holding it to the spindle are tight, and the disc is running centered in the caliper, there's not a lot other potential culprits other than the pad and disc interface.

As for disc noise with drill holes and slots...that is a valid possibility. It doesn't happen on all cars, but we do see it on some. In the hierarchy of noise, from quietest to noisiest would be plain face, straight slot, J Hook Slot, Drill holes. The noise you get from holes or slots is typically not a groaning...it is more of a scraping or whirring noise. You would hear it when you drive next to a wall and the sound bounces off the wall and back to you.

The fact that the issues are speed-dependent are really odd. Normally with a pad deposit you will feel it most of the time, and it tends to be more severe/violent the harder you're stopping.

The only way you guys are going to isolate the issue is to change one thing at a time on the car.
1. Change the brake pads out to something non-oem and leave everything else alone...check for noise.
2. If still present, put on fresh discs and check again.
3. If you change out the pads and discs and the noise is still present, you have something else going on.

Anybody with this problem live around Charlotte, NC? If so, we'd be happy to look at the car and see if we can isolate the issue and its cause. My gut tells me that a proper bed-in will take care of this issue. A proper bed-in is typically more aggressive than what people do. Most people back off too early, aren't braking hard enough, aren't scrubbing enough speed, etc. Watch my videos...they show exactly what I'm talking about better than I can write it. Thanks.

Originally Posted by Powerslide

Thanks for taking the time to write that excellent reply and advice - definitely appreciate that! I'll keep updating this thread as I learn more or as developments continue...

Thank You guys for your help, hopefilly we can resolve this issue...

[jritt@essex]

Originally Posted by Powerslide

Thanks for taking the time to write that excellent reply and advice - definitely appreciate that! I'll keep updating this thread as I learn more or as developments continue...

No worries. I hate that we can't get our hands on the car with the issue and see it firsthand! My engineering director would probably have a fix in three minutes!

[Powerslide]

So - back from the dealership with new pads/rotors front and rear - I just started a new thread/poll for break-in procedures used by people, and whether each person has had the judder come back - regardless of which break-in procedure was used before/after rotor/pad replacement.

Nobody is sure why the judder developed in the first place. Although I'd love to know the exact answer why - I'd still be more than happy if the problem never came back again (even without knowing).

Guess we should all periodically check back in on this thread with any new developments/information as we go - the more collective knowledge we assemble here - hopefully the more likely a "root cause" will be identified and a more long-term solution also identified...