Warped Rotors

[rushbmw]

Originally Posted by ec

Rushbmw, I have the same vibration when I brake and I have Elbrus I02 wheels. It occurs for me with light braking at around 30-60 mph. I don't know if that's just coincidence or what. It just started a couple of weeks ago and I've had the rims on for 2 months. I'm hoping it's not the rotors (maybe the brake pads are uneven?) because I don't want to go through the hassle of trying to get BMW replace them.

EC, Wow! Thats exactly what speed range I get my vibration at and its only under light braking. Its also happen after a month of having the rims on. The harder I press the brakes the less it vibrates but it can also be because speed is reducing. I had BMW already replace the rotors, pads and sensors and with in two weeks the warped rotors were back!. I wonder if anyone else out there with these rims notice this. If it is the rims I will be happy but at the same time really pissed.

[rushbmw]

Originally Posted by jeremyc74

I'm going to guess you're not warping the rotors. If the winter rims weren't properly machined, or were drastically overtorqued that might have something to do with it, but I think you're probably getting deposits from the pads sticking to them.

Give this a try and see what happens:

Warm everything up with 10-20 minutes of normal driving, then take the car up to about 80MPH on a nice clear, straight road, and stop it as hard as you can, down to about 10MPH. Drive for a few minutes and then repeat. I'm betting the problem goes away.

I've had metallugists tell me that warped rotors are a myth on street cars, and that the problem is usually due to corrosion or deposits left from the pads. That's why a quick turning that barely takes off any material will put them back in shape. It's worth a try and see if they're right.


This isn't the only time I've heard this, but here's an example of what i'm talking about:

jeremy, I sort already tried re-bedding my rotors and pads like you suggested. It didnt seem to help. However, I really couldnt generate hard braking with my winter rim set because the tires would break lose before I can get the rotors hot.
Can't wait for NY weather to change were I can go back to my stock rims.

[ec]

Just a follow up. The vibration when braking became terribly noticeable. So I went to the dealer and they described it as a severe brake pad imprint problem. They looked at the brakes and found that the front rotors had "run-off". Apparently this means that there was a subtle right-left movement of the rotors when in motion. Anyways, they replaced the front two rotors and the vibration is now gone. It's just been one day though, so well see...

[jeremyc74]

It's interesting that there seem to be a few people with this problem. A bad batch of rotors maybe? Keep us posted.

[Robert]

Originally Posted by jeremyc74

I've had metallugists tell me that warped rotors are a myth on street cars, and that the problem is usually due to corrosion or deposits left from the pads. That's why a quick turning that barely takes off any material will put them back in shape. It's worth a try and see if they're right.


This isn't the only time I've heard this, but here's an example of what i'm talking about:

Interesting. I use to own a Volvo, big and heavy european car, and I would warp the rotor all the time on the 405, given I was younger and more aggressive driver back then. I had gone through 2 sets of front rotors from repeated 0 to 60 back to 0 stop-and-go traffic until I switched to Cyrofreezed rotor. Those lasted until I got rid of the S70.

[rushbmw]

Originally Posted by ec

Just a follow up. The vibration when braking became terribly noticeable. So I went to the dealer and they described it as a severe brake pad imprint problem. They looked at the brakes and found that the front rotors had "run-off". Apparently this means that there was a subtle right-left movement of the rotors when in motion. Anyways, they replaced the front two rotors and the vibration is now gone. It's just been one day though, so well see...

EC, keep me posted about your rotors. My car was fine for about two weeks after they replaced the rotors. Now Im back too having the same
vibration. I have to put the stock rims back on to see if the problem is still there. Damn winter is taking too long!

[ec]

Hey Rushbmw

Well it's been over a month since they changed the rotors and so far so good. No vibration yet (knock on wood). I'm thinking of changing back to summer tires soon.