Cow Bell Noise: Losing Patience

[elh0102]

I guess folks need different levels of instruction. I thought a close-up photo of the removal of the spring offered sufficient content. Anyway, the tech at the dealer said he had removed and lubed these springs in several M3 cars, and it was the problem in each case, including mine. He had not seen the problem in any other models. If this is the issue in your car, you can definitely hear the difference in this sound, compared to something being caught between rotor and shield. The sounds are similar (having heard both), but this definitely has a “springy” quality that is unmistakable. And, if the issue is something caught in there, the object can easily be dislodged by pressing the shield away from the rotor with a long screwdriver. If nothing falls out, then you have another problem, which may be these springs.

[Seattle S65B40]

Originally Posted by elh0102

I guess folks need different levels of instruction. I thought a close-up photo of the removal of the spring offered sufficient content. Anyway, the tech at the dealer said he had removed and lubed these springs in several M3 cars, and it was the problem in each case, including mine. He had not seen the problem in any other models. If this is the issue in your car, you can definitely hear the difference in this sound, compared to something being caught between rotor and shield. The sounds are similar (having heard both), but this definitely has a “springy” quality that is unmistakable. And, if the issue is something caught in there, the object can easily be dislodged by pressing the shield away from the rotor with a long screwdriver. If nothing falls out, then you have another problem, which may be these springs.

I don't believe i've ever had the parking brake issue. I think you're right, if that's the issue, it has more of a springy and consistent type of sound (i recall a video someone posted that was a very consistent sound). If it's a pebble, it's going to sound more inconsistent and tumbley (like in my video). I for one appreciate your effort and follow up on this thread and will have my SA check out the e brake springs next time I'm in.

[OC3]

Man, in reading these threads, I thought cow bell noise was a thing of fable, something that happens to others. Well, it happened on my car after a track day this past Sunday. The noise was coming from passenger side, rear wheel/corner. But, fortunately, the noise went away after driving & stopping, driving & stopping, etc, for about 5 minutes.

[DrakeKemper]

Originally Posted by Seattle S65B40

I've now had my car serviced twice for this issue twice in the past 3 weeks and it's as bad as its ever been.

I've already had both rear bearings replaced and diff fluid changed. I highly doubt it is a stone/pebble trapped between the caliper and heat shield, as some have suggested. This makes more of an inconsistent tumbling sound, as my guess is that would tend to make more of a consistent sound. I really tried to drive it off tonight, but it is now doing it continuously. I have no choice but to take it back to the dealer, but was hoping to get some help diagnosing it.

Here's a video:

If you have a stock exhaust, a LOT of stuck can get stuck on top of it, its a fairly common problem. May want to check that. It sounds like a Pebble IN your exhaust lol.

[llis]

Got pebbles into the right rear wheel after driving on some gravel. Yipes. Went away after driving around a bit.

[Seattle S65B40]

Originally Posted by DrakeKemper

If you have a stock exhaust, a LOT of stuck can get stuck on top of it, its a fairly common problem. May want to check that. It sounds like a Pebble IN your exhaust lol.

Mine was already diagnosed as a pebble in the rotor/brake shield. Already good. It came back for a bit and then was all good again.

BTW, post some pics of the '91 GF. Don't you know, it's Pics or GTFO around here...

[mkoesel]

Has anyone ever actually been able to either see the pebble stuck in the brake shield by using a small trouble light, or removed the shield to see the pebble fall out?

Obviously some of these cases are pebbles, and some are not. For some folks who have recurring problems, it seems more likely that it is something else that happens to come and go. I realize other causes are discussed in this thread already, but it seems the vast majority of folks are willing to buy that it is a pebble in their case without ever really being able to verify it. Just an arbitrary, salient point to consider.

[Seattle S65B40]

Originally Posted by mkoesel

Has anyone ever actually been able to either see the pebble stuck in the brake shield by using a small trouble light, or removed the shield to see the pebble fall out?

Obviously some of these cases are pebbles, and some are not. For some folks who have recurring problems, it seems more likely that it is something else that happens to come and go. I realize other causes are discussed in this thread already, but it seems the vast majority of folks are willing to buy that it is a pebble in their case without ever really being able to verify it. Just an arbitrary, salient point to consider.

Yes - showed up at Service center with noise. Shop foreman takes car, says he'd be right back. 5 minutes later showed up and handed me a pebble. Said here's your problem. No sound after that. it came back once since then but went away again, so i assume it was another pebble that fell out .

[Jaypod]

Originally Posted by mkoesel

Has anyone ever actually been able to either see the pebble stuck in the brake shield by using a small trouble light, or removed the shield to see the pebble fall out?

Obviously some of these cases are pebbles, and some are not. For some folks who have recurring problems, it seems more likely that it is something else that happens to come and go. I realize other causes are discussed in this thread already, but it seems the vast majority of folks are willing to buy that it is a pebble in their case without ever really being able to verify it. Just an arbitrary, salient point to consider.

I have personally removed a pebble 3 or four times. I have also seen a similar instance where it was actually the heat shield making the noise at the track on someone else's M3. I pushed the heat shield back a bit for them and the sound went away.

[mkoesel]

Thanks guys.

Start saving those pebbles instead of tossing them back to ground, ok? If we all do our parts, eventually we can rid the world of this nuissance and make it safe for M3's everywhere. I do this same thing with soy burgers and Justin Beeber albums - whenever the opportunity presents itself.

[Seattle S65B40]

Originally Posted by mkoesel

Thanks guys.

Start saving those pebbles instead of tossing them back to ground, ok? If we all do our parts, eventually we can rid the world of this nuissance and make it safe for M3's everywhere. I do this same thing with soy burgers and Justin Beeber albums - whenever the opportunity presents itself.

haha - like someone else mentioned, you're on a roll lately!

[xchosun1x]

i had my first cow bell experience in a parking structure the other day. Only seems to happen under slow crawling speeds. The fact that I was in a structure made the noise echo and the passer-by-ers had funny puzzling look on their face.

The next day the sound disappeared and hasn't come back

[robotrenegade]

I'm in the club

[mot]

It took a few weeks for it to naturally go away.

[Bomis]

Just got the cow bell noise too

I only get the noise after using the parking brake...

[serranot]

I'm beginning to think that pebbles are getting into the parking brake drum area as opposed to merely the rotor/shield area. They would be putting pressure on the parking shoes and moving them around. I can see how greasing the springs would help quiet the noise, but really not solve the problem.

Thing is, I have never disassembled that part of the car. For those of you that have, is this a viable theory?

[stevenross]

I have the same problem and am going in for service this week. I think it's the e brake as I believe a valet drove the car a few feet only to realize the emergency brake was on. Will let you know how it's resolved.

[jjjheimer]

I heard the exact sound in the video above when reversing and my solution was to flick the metal dust shields behind each of the brake rotors. While I did not notice pebbles/rock falling out of the dust shield the cowbell sound was gone after that and hasn't come back.

[Mr. ///M3 RD]

Reminds me of the time someone asked me in Switzerland;-

"Why do the cows here wear cow bells?"

I simply said ...

"So they don't fall asleep while they are grassing" (feeding of course on the grass LOL).

[stevenross]

have exact same problem.. bringing it into dealer next week.. will let everyone know the solution.. will mention ebrake adjustment, heat shield, etc.

[Oreokid24]

Add me to the list. Picked up car at the PC in SC on Friday afternoon. Nice leisurely drive back to PA, back roads, some highway, no cruise.. followed all the rules. DCT so I use the parking brake when parking.
First heard it yesterday, from LR at toll booth 30 miles from home ~600 miles on it. Had not heard it before. Then heard it again pulling into driveway. Very slow.. just rolling, both forwards and backwards. Definitely like the sound in the video.
And as everyone else said.. very embarrassing sound. Will poke at heat shield and see. Will check with dealer on Monday.
ugh...

[Beck white]

Thank you now I finally know what the hell that noise is too; I hear it prior to mobbing rancho. I thought it was just the extreme heat of the exhaust after the run