Warped Rotors?!

[CarolinaM5]

Hey guys. Thought I'd write a little update. I recently developed a bad vibration under braking that was transmitted into the steering wheel. I've only got 3700 miles on my car thus far. The problem first started out as a very mild vibration at about 75mph. I thought perhaps the balance was off. We had the wheels rebalanced and road forced, and the vibration got much better, but then when I paid a bit more attention I noticed the vibration was occuring under braking between 65-75mph. Took it over to local BMW dealership today and shop foreman came with me for ride. Vibration reproduced, roaring sound from the rotors also heard. After the test ride with shop foreman, new rotors now on order.....before you guys ask, the car has never been tracked!!! I think the weight of these cars is playing some role in rotors warping prematurely. Anyone else had this experience yet?!

[johntomferg]

Interesting post CarolinaM5. Not in agreement yet with the conclusion that it is a system problem due to vehicle weight. [I'm well past your mileage and I drive mine pretty hard without any indication of this...]

Can you elaborate some more on the finding by the shop?

Was it just the fronts? the rears? or both?
Did they indicate that the brake may have been dragging and causing undue/excess heat? Or a problem with the ABS / Automatic Brake drying system contributing?

Thanks in advance.

[PatrickC23]

Can aftermarket wheels cause warped rotors? I had them on my C63 and felt vibration braking as well.

[hinckley]

Carolina, does your car sit outside for long periods in between drives? I had big problems with warped rotors in my 08 E60 due to that.

[CarolinaM5]

Originally Posted by johntomferg

Interesting post CarolinaM5. Not in agreement yet with the conclusion that it is a system problem due to vehicle weight. [I'm well past your mileage and I drive mine pretty hard without any indication of this...]

Can you elaborate some more on the finding by the shop?

Was it just the fronts? the rears? or both?
Did they indicate that the brake may have been dragging and causing undue/excess heat? Or a problem with the ABS / Automatic Brake drying system contributing?

Thanks in advance.

It appears that the front rotors are the culprit as vibration was felt in steering wheel and not in seat. The second point you have is very interesting, and I thought of this earlier myself, but I haven't had any ABS lights to show to indicate that thats the problem. However an X6M owner said he had a similar issue in his car.

[CarolinaM5]

Originally Posted by Patsc23

Can aftermarket wheels cause warped rotors? I had them on my C63 and felt vibration braking as well.

I suppose anything is possible, but the wheels I have are good quality and hub centric. However, I have heard of rotors being warped with lug nuts being improperly torqued. However I insisted that my wheel lugs be hand torqued to spec which was done when installation occured. I've had plenty of aftermarket wheels and never had this issue to occur before.

[CarolinaM5]

Originally Posted by hinckley

Carolina, does your car sit outside for long periods in between drives? I had big problems with warped rotors in my 08 E60 due to that.

Car has been garage kept since day one. When I'm at work it sits outside, but this is only 2 days a week max. What kind of problems did you have when your car sat outside?

[bm5bullit]

Panic stops during the first 200 miles will usually do this also.

[thebishman]

Floating rotors generally always make a "roaring" type of noise so this is normal. I almost guarantee that this is pad deposition on the rotors, especially if you've never taken the time to bed in both pads and rotors properly. Go out and brake as hard as possible but without engaging the ABS from 50 mph down to 5 mph; do not come to a stop! Drive for 5 minutes to cool the brakes then repeat the above from 60 mph down to 5 mph. Again drive long enough without touching the brakes to cool the brakes down. Repeat the above from 70 mph and then 80 mph. If you can, slow down from 80 mph a couple of times. Of course, always be safe. The above will remove any excess pad deposition on the rotors and will also condition the pads and rotors. See if the vibration under braking goes away.
Bish

[bm5bullit]

Originally Posted by thebishman

Floating rotors generally always make a "roaring" type of noise so this is normal. I almost guarantee that this is pad deposition on the rotors, especially if you've never taken the time to bed in both pads and rotors properly. Go out and brake as hard as possible but without engaging the ABS from 50 mph down to 5 mph; do not come to a stop! Drive for 5 minutes to cool the brakes then repeat the above from 60 mph down to 5 mph. Again drive long enough without touching the brakes to cool the brakes down. Repeat the above from 70 mph and then 80 mph. If you can, slow down from 80 mph a couple of times. Of course, always be safe. The above will remove any excess pad deposition on the rotors and will also condition the pads and rotors. See if the vibration under braking goes away.
Bish

Agree 100% as I have done this before to bed in rotors/brakes. This a lot like the old school process to break in a "built" motor.

[CarolinaM5]

Originally Posted by thebishman

Floating rotors generally always make a "roaring" type of noise so this is normal. I almost guarantee that this is pad deposition on the rotors, especially if you've never taken the time to bed in both pads and rotors properly. Go out and brake as hard as possible but without engaging the ABS from 50 mph down to 5 mph; do not come to a stop! Drive for 5 minutes to cool the brakes then repeat the above from 60 mph down to 5 mph. Again drive long enough without touching the brakes to cool the brakes down. Repeat the above from 70 mph and then 80 mph. If you can, slow down from 80 mph a couple of times. Of course, always be safe. The above will remove any excess pad deposition on the rotors and will also condition the pads and rotors. See if the vibration under braking goes away.
Bish

Thanks for the advice man, will perform this tongiht or tomorrow and see if it makes a difference. On my track car I always bedded in brakes, but that was with high friction pads. Will give it a go on the M.

[evanevery]

Me Too! Me Too!

3500 miles 2013 M6 Convertible: http://www.6post.com/forums/showthread.php?p=13672391

I just posted the above query in the M6 forum and another user pointed me to your posting!

Perhaps BMW has an issue with some of the rotors on the M5/M6 vehicles? What was your build date? (Mine was October)...

[CarolinaM5]

Originally Posted by evanevery

Me Too! Me Too!

3500 miles 2013 M6 Convertible: http://www.6post.com/forums/showthread.php?p=13672391

I just posted the above query in the M6 forum and another user pointed me to your posting!

Perhaps BMW has an issue with some of the rotors on the M5/M6 vehicles? What was your build date? (Mine was October)...

I'm thinking that this is the case, my build date was in August.

[BarryB]

I have the same thing but from 55-45mph. No track days. I am lowered with spacers waiting for the dealer to blame those.....
I took the spacers off and it made no diff.

[CarolinaM5]

Alright, update on this guys, we had the rotors replaced and the vibration is completely gone. When measured the rotors were out of round 5 one-thousandths on both sides. I tried bish's tip of trying to get embedded material off the rotors but it didn't work, vibration remained. Riding very smoothly now....have no earthly idea how these rotors became warped........btw, the total parts costs would have been $1500 had there been no warranty, that included rotors, pads, and sensors.