[das340i]

Hi, I have a '16 340i and I've been having issues with the front brakes "warping" the discs. Of course the first items I have tried to replace are the pads and rotors. Followed all bedding procedures of course...led me to believe that the hubs were warped; they are not. What other concerns could be causing the brakes to "warp" like this? Note this pulsation is enough to vibrate the entire car. Thrust arms have been replaced last year, no signs of wear on the control arms... I suspect it could be a failed abs sensor or strut mounts. Thoughts?

[Markyboyt]

Random thought, have the wheels been powder coated somewhere that has also coated the mating face of the wheel where it contacts the disc? Seen it before where this had happened and stopped the heat transfer from the discs to the wheels causing the brakes to overheat and warp repeatedly.

[das340i]

They haven’t been but that would definitely make sense!

[das340i]

Desperate for some info! Anything would help!!!

[cfm56d7b]

What rotors and brake pads does your car have? OEM or aftermarket?

[das340i]

I have zimmerman rotors and EBC yellow stuff pads. I've replaced the pads and rotors with factory ones twice before...didn't make a difference. Pulsation went away for a very short time then quickly returned.

[das340i]

Note the pulsation only really seems to happen at highway speeds (typically gets worse as the brakes get warmer) I do also feel vibration in the seat which would obviously indicate there is vibration from the rear.

[cfm56d7b]

Originally Posted by das340i

I have zimmerman rotors and EBC yellow stuff pads. I've replaced the pads and rotors with factory ones twice before...didn't make a difference. Pulsation went away for a very short time then quickly returned.

This is helpful. Did you replace rotors and EBC yellow stuff pads at the same?

After both have been replaced, when did the pulsating symptoms appear? How many miles after the installation?

[das340i]

Yes both were replaced at the same time, replaced them in an attempt to resolve the pulsation. Took about 2000-3000 miles for it to return. Followed the bedding procedure as per yellow stuff. No pulsation during the bedding process. Let them cool after the procedure ( drove up the highway for 20 minutes without stopping)

[frenchi]

Originally Posted by das340i

Yes both were replaced at the same time, replaced them in an attempt to resolve the pulsation. Took about 2000-3000 miles for it to return. Followed the bedding procedure as per yellow stuff. No pulsation during the bedding process. Let them cool after the procedure ( drove up the highway for 20 minutes without stopping)

You got a sticking brake caliper,almost always at the back.
I got that as well and spend months chasing as it happens par intermittence and mostly on high speed above 60mph. Remove your rear breaks and check the pads,you will got one side slightly more used than the other.

[das340i]

Thanks, would make sense. How significant was your pad wear compared to the other? Was the pad uneven or just more worn than the other?

[frenchi]

Originally Posted by das340i

Thanks, would make sense. How significant was your pad wear compared to the other? Was the pad uneven or just more worn than the other?

Surprisingly there was just a few millimetres of difference between both sides that's why i didn't spot it on first try.Clean very well your rear pistons and try to check by Hand if they push smoothly

[das340i]

Makes sense, thanks for the info I'll give it a try