Are these rotors done?

[Erickuokwa]

After I car washed, I let the car sit for a day. The next day I felt shaking when I was braking. investigating later I found this

[GRM Scott]

Do a few fairly hard stops in a row to see if solid brake pressure machines the surface rust off the rotor, and if that eliminates the vibration. You'd be amazed how aggressively the brake pad manufacturers I've ridden with bed-in new pads, get going pretty fast and then threshold brake to haul it down to 15mph or so, then repeat several times till they're good and hot.

[PACarGuy]

Looks like uneven pad material transfer, or the car sat when the brakes were super hot. They can be saved with some hard stops using semi-met pads or race pads per GRM Scott's comment above, or some sanding with garnet paper, etc. per this article:

http://www.stoptech.com/technical-su...nd-other-myths

[dparm]

Try to re-bed them and scrape that stuff off:

https://www.zeckhausen.com/catalog/i...Path=6446_6443

[roastbeef]

rotors look visually healthy. do some hard stops to knock off those pad deposits.

[TrueToBMW]

So thats the result after having braked a few times during normal driving? Or is that just backing it down the driveway and they started shaking? Give us a little more info, or just try everything that was mentioned above and go from there.

[Scrippy]

Not sure what the big deal is? A few stops and the rust build up will be gone. It may be an M3 but it's still just a car. Go to a dealership and you will see a lot of the cars like this. It comes from not driving.

[Solo_M_Tech]

Part out?

[Erickuokwa]

Originally Posted by Scrippy

Not sure what the big deal is? A few stops and the rust build up will be gone. It may be an M3 but it's still just a car. Go to a dealership and you will see a lot of the cars like this. It comes from not driving.

I've done a good amount of hard stops 70-20 and it hasn't gone away and it's still shaking the car, I'm going to give it a week to see if anything happens. The car had 120k miles and probably still the original rotors so might be time to change them

[Erickuokwa]

Originally Posted by Fubar_M3

Part out?

What ya looking for lol

[Solo_M_Tech]

Originally Posted by Erickuokwa

What ya looking for lol

Not your rusty rotors thats for sure.

[Erickuokwa]

Originally Posted by Fubar_M3

Not your rusty rotors thats for sure.

Ahaha I dont even want these rusty rotors D:

[Spun Crankhub]

Car is totaled. Sell me all your mods.

[pbonsalb]

Those rotors look great. Barely any wear. You probably have not seen rust on your rotors before because you park inside and don’t drive in the rain. If you use your brakes, the surface rust will disappear. It will still be in the drilled holes and vanes but won’t affect anything other than looks. My drilled (actually probably cast) holes were rusted closed and my vanes choked with rust. I got another year by drilling out the rust and hammering the rotors to knock rust out if the vanes. I had huge lips on the outer circumference from wear — the pads did not sweep there.

[Helmsman]

Like pbonsalb says, can't see much lips here? M3 discs are expensive mate, take wheels off investigate, clean calipers. Do some proper "bed in" breaking. Evaluate.

Good luck!

[WingZeroX5]

buy a set of race pads and run them for a short time, especially when the brakes are cold. Swap back to your street pads and try again.

[TrueToBMW]

From the original post, it seems as if he drove the car, and some of the rotor surface rust came off, while some stayed on, and the braking wasn't normal, maybe pulsating?

If that's the case it would seem like the rotors are way out of whack, maybe I misunderstood the original issue.

Anyway, I'll stop chiming in until the OP can clarify.

[Scrippy]

Originally Posted by TrueToBMW

From the original post, it seems as if he drove the car, and some of the rotor surface rust came off, while some stayed on, and the braking wasn't normal, maybe pulsating?

If that's the case it would seem like the rotors are way out of whack, maybe I misunderstood the original issue.

Anyway, I'll stop chiming in until the OP can clarify.

If driving the car NORMALLY doesn't remove the rust or pad material......taking the wheels off and removing the rotors for a turning at a shop is very easy. Most shops charge like $10-20 bucks to turn them. You just need to be explicit in that you want minimal taken off ONLY FOR DEBRIS REMOVAL AND NOT A TOTAL RESURFACING. Minimum thickness is stamped on the rotor hats, so they can't f'up.

[pbonsalb]

I seriously doubt the op warped the rotors. He simply needs to drive the car and use the brakes. Not treat it like a delicate work of art. If that does not remove the deposits, I’d borrow a set of race pads and then drive the car. Only as a last resort would I take the rotors to a machine shop. Those rotors look practically new to me.

[TrueToBMW]

Originally Posted by pbonsalb

I seriously doubt the op warped the rotors. He simply needs to drive the car and use the brakes. Not treat it like a delicate work of art. If that does not remove the deposits, I'd borrow a set of race pads and then drive the car. Only as a last resort would I take the rotors to a machine shop. Those rotors look practically new to me.

I agree, especially not your average Jiffy Lube type shop, I used to have my rotors resurfaced on my track bikes, but needed to find a race shop in order for them to get done properly.

Not sure if just any brake & tire shop would be able to do the same quality work as a vetted race shop, or are they all the same type of machines and/or processes of getting it done?

[Townending]

I recently went through this a few weeks ago, scrubbing with race pads solved the issue for me.

After I completed the scrubbing I tossed on a new set of pads, brakes feel great, no issues at all.

https://www.m3post.com/forums/showthread.php?t=1384226

[Scrippy]

I really have no idea why everyone acts like the M3 is a spaceship engineered by NASA. Turning M3 rotors can be done at ANY auto shop. Rotors are rotors and anyone can put them in a turning machine....set the desired depth and walk away while the machine does it all. Cross drilled and/or slotted makes no difference.