Brake Sensor Question

[budman1]

OK, my 335 suffers from the 'brake squeal' when accelerating from a standing start to around 20 mph. In the grand scheme of things, I guess it's not a big deal. However, the squeal irritates me.

From a lot of searching on this forum and other web boards, it seems the issue is caused by the rear brake sensor rubbing into the rotor. So, here's my question. Can I just disconnect the brake sensor from the caliper (tie it up somewhere) and not cause a brake light to come on?

OK, Ok, I know there is an easy way to see what will happen. Just thought I'd post here to see if others might know.

[Babagnush]

Take it to the dealership. This is a known issue.

[Critter7r]

Right... warranty fixes it for free.

And you'd have to remove the pads in order to remove the sensor from the pad for it to stop squealing. You wouldn't be able to just unplug the sensor.

[Sdeprima]

Allright, well i literally just went through the same problem about three weeks ago. It is the sensor, and it won't go away. I live in miami, and i took it to the dealership twice, both times they claimed that they were unable to replicate the noise, so I had to go down to the dealership, get a technician in my car, and replicate the noise, which of course i did easily within five minutes, which makes me wonder how they were "unable" to replicate it themselves in the first place. After the tech heard the noise, we went back, talked with my advisor, and he said that they can't just replace the sensor, they have to replace the whole brake assembly, that's just how bmw north america wants things done i'm assuming. Anyways, apparently some brake noise is part of normal driving conditions, so even though they know what the problem is, they couldn't fix it as a bmw warranty job because some brake noise is part of every day driving according to bmw. The entire brake assembly gets replaced by bmw when the pads and rotors are worn down to certain specs, but of course mine were not even close. Luckily for me, I've developed a pretty great relationship with my service advisor, and he heard the noise and refused to let me drive home and have to deal with brakes that squeal at low speed, so he had the tech go find some worn down 335 brakes laying around and said that those were my brakes, and two hours later, i have brand new rear brakes and no more noise :buttrock So my advice to you is go to the dealership, make sure they hear the noise, and push them until they fix it, they might not be ticky tack and just give you new brakes, or they might feed you a bunch of bs like they did to me in the beginning, but if they do, just push and push till they fix it. Every service advisor makes money on the work they advise, so the more they advise, the more they get paid, so its in the advisors best interest to put a thousand dollars worth of brakes on your car instead of telling you that your SOL :evil2

[E92!Dreier]

Allright, well i literally just went through the same problem about three weeks ago. It is the sensor, and it won't go away. I live in miami, and i took it to the dealership twice, both times they claimed that they were unable to replicate the noise, so I had to go down to the dealership, get a technician in my car, and replicate the noise, which of course i did easily within five minutes, which makes me wonder how they were "unable" to replicate it themselves in the first place. After the tech heard the noise, we went back, talked with my advisor, and he said that they can't just replace the sensor, they have to replace the whole brake assembly, that's just how bmw north america wants things done i'm assuming. Anyways, apparently some brake noise is part of normal driving conditions, so even though they know what the problem is, they couldn't fix it as a bmw warranty job because some brake noise is part of every day driving according to bmw. The entire brake assembly gets replaced by bmw when the pads and rotors are worn down to certain specs, but of course mine were not even close. Luckily for me, I've developed a pretty great relationship with my service advisor, and he heard the noise and refused to let me drive home and have to deal with brakes that squeal at low speed, so he had the tech go find some worn down 335 brakes laying around and said that those were my brakes, and two hours later, i have brand new rear brakes and no more noise :buttrock So my advice to you is go to the dealership, make sure they hear the noise, and push them until they fix it, they might not be ticky tack and just give you new brakes, or they might feed you a bunch of bs like they did to me in the beginning, but if they do, just push and push till they fix it. Every service advisor makes money on the work they advise, so the more they advise, the more they get paid, so its in the advisors best interest to put a thousand dollars worth of brakes on your car instead of telling you that your SOL :evil2

well said.

[mryakan]

Every service advisor makes money on the work they advise, so the more they advise, the more they get paid, so its in the advisors best interest to put a thousand dollars worth of brakes on your car instead of telling you that your SOL :evil2
I am sure some of our resident techs will weigh in on this, but I know from my brother who is a dealer technician that warranty works sometimes pays less than what it actually takes to do the job and certainly less than the same work done outside warranty. So on a busy day, the poor tech who is doing a warranty claim for a difficult customer (I am not pointing fingers at you here, just talking in general) is in fact losing money. My brother told me a couple of stories of his buddy techs working 8 hrs to fix a problem under warranty but the manufacturer only pays them an hour or two, so not only did they work 6 hrs for free, they may have also missed more hours because in those 6 hrs they could have sold more than 6 hrs worth of work. I just thought I'd highlight this, it is not an issue when we go in for valid reason, but maybe something to keep in mind when we go in for trivial stuff, and again I am not saying the issue is here trivial or not.

[Critter7r]

Allright, well i literally just went through the same problem about three weeks ago. It is the sensor, and it won't go away. I live in miami, and i took it to the dealership twice, both times they claimed that they were unable to replicate the noise, so I had to go down to the dealership, get a technician in my car, and replicate the noise, which of course i did easily within five minutes, which makes me wonder how they were "unable" to replicate it themselves in the first place. After the tech heard the noise, we went back, talked with my advisor, and he said that they can't just replace the sensor, they have to replace the whole brake assembly, that's just how bmw north america wants things done i'm assuming. Anyways, apparently some brake noise is part of normal driving conditions, so even though they know what the problem is, they couldn't fix it as a bmw warranty job because some brake noise is part of every day driving according to bmw. The entire brake assembly gets replaced by bmw when the pads and rotors are worn down to certain specs, but of course mine were not even close. Luckily for me, I've developed a pretty great relationship with my service advisor, and he heard the noise and refused to let me drive home and have to deal with brakes that squeal at low speed, so he had the tech go find some worn down 335 brakes laying around and said that those were my brakes, and two hours later, i have brand new rear brakes and no more noise :buttrock So my advice to you is go to the dealership, make sure they hear the noise, and push them until they fix it, they might not be ticky tack and just give you new brakes, or they might feed you a bunch of bs like they did to me in the beginning, but if they do, just push and push till they fix it. Every service advisor makes money on the work they advise, so the more they advise, the more they get paid, so its in the advisors best interest to put a thousand dollars worth of brakes on your car instead of telling you that your SOL :evil2


well said.


I couldn't disagree more... (shocker, I know, right?)

Anyhow... how retarded is your dealership to not just replace the brake pads and sensor like the bulletin addressing this problem states????

Here's the correction for the noise...

SUBJECT
Brake Squeal from Pad Wear Sensor

MODEL
E90, E91, E92, E93 (3 Series)



SITUATION
Depending on the driving conditions, the occasional brake squeak and/or squeal is normal. The condition listed in this bulletin occurs during all light to moderate brake applications and is caused by contact between the brake pad wear sensor and the brake rotor/disc. This situation can occur on the front or rear axle brakes.


CAUSE
The geometry of the brake wear sensor, combined with individual driving habits, can result in a particular wear pattern which causes a squeaking and/or squealing noise whenever the brakes are applied with light to moderate force.


"CORRECTION
In the case of a customer complaint, road test the vehicle to determine the source of the noise. If the noise is coming from the brake system, inspect the brake pad wear sensor of the affected axle. If the sensor is in contact with the rotor/disc, remove the sensor and drive the vehicle.

If the noise is not eliminated, further diagnosis is required to determine the cause of the noise.

If the noise is eliminated, replace the brake pads and wear sensor of the affected axle."


What imbiciles go through the trouble of trying to defraud BMW by saying that your brakes are worn down below minimums to get this fixed?? What a bunch of idiots.

I know Sdeprima doesn't care, either way he got his brakes fixed, but I'm embarrassed that the dealer went through all that malarky. (Or at least said they did... maybe they made it all up so he'd think they did a lot more work then they did).

[Beer Goggles]

You are not looking at this the right way. Squeal under braking is normal. Squeal on acceleration is NOT normal and isn't caused by anything but a bad design.

They fixed my squeal but GRINDING down a sensor at the dealer. I don't think they replaced anything....or I might have to look they may have replaced the rear brakes the second time. I know my car squeals under light braking now...which I dont really care. It's not the horrible sound it made before.


Also, techs get paid on a fixed rate...so yes sometimes they LOSE money, and other times they make more than they should. If the system really wasn't working....there would be no techs right? I don't get paid more for working 16 hour days either. Welcome to life.

[mryakan]

Also, techs get paid on a fixed rate...so yes sometimes they LOSE money, and other times they make more than they should. If the system really wasn't working....there would be no techs right? I don't get paid more for working 16 hour days either. Welcome to life.
Yeah no kidding, I don't either, but I was just highlighting why sometimes techs dislike working on some warranty issues esp. one that take more time to figure out than it pays. There is a reason they tell you they can't reproduce something sometimes, because if they took all the time to reproduce it but only get paid a fraction of that then they are in essence losing money, so they spend some minimal amount of time and if they can't reproduce it they send you back home. I think not many people realize how this system works, I certainly didn't before.

[Beer Goggles]

Yeah no kidding, I don't either, but I was just highlighting why sometimes techs dislike working on some warranty issues esp. one that take more time to figure out than it pays. There is a reason they tell you they can't reproduce something sometimes, because if they took all the time to reproduce it but only get paid a fraction of that then they are in essence losing money, so they spend some minimal amount of time and if they can't reproduce it they send you back home. I think not many people realize how this system works, I certainly didn't before.

The average is how long it should take. I had friends who worked with warranty stuff too and they challenge the company to come down and do it in the time alloted, but he also said some warranty stuff was money. So it works out. As i said...if it didn't work out.....it would be different.

[budman1]

Thanks for the replies. I will likely schedule a service visit in the near future.

[mihalis]

Yeah no kidding, I don't either, but I was just highlighting why sometimes techs dislike working on some warranty issues esp. one that take more time to figure out than it pays. There is a reason they tell you they can't reproduce something sometimes, because if they took all the time to reproduce it but only get paid a fraction of that then they are in essence losing money, so they spend some minimal amount of time and if they can't reproduce it they send you back home. I think not many people realize how this system works, I certainly didn't before.

My dealer was always good to me, especially when I started spending some money there, but when I called another dealer, they pretty much told me that they are not going to repair anything under warranty, so I never bothered stepping foot in there. Why would I go to dealer that is not willing to work on my car concerns and wants to charge me for everything, even under the warranty period. It all depends on the dealer and the people who work there.

Good luck :)

[Beer Goggles]

My dealer was always good to me, especially when I started spending some money there, but when I called another dealer, they pretty much told me that they are not going to repair anything under warranty, so I never bothered stepping foot in there. Why would I go to dealer that is not willing to work on my car concerns and wants to charge me for everything, even under the warranty period. It all depends on the dealer and the people who work there.

Good luck :)


What? I'm assuming that dealer is going out of business.

[cemman]

Although this has been beaten to death, I too had the "brake squeal" upon acceleration problem. I just had the car in for routine servicing and asked the dealer to fix it. Although the SA had no idea what I was talking about, I let him know there was a service bulletin and this was a known issue. He's a pretty good guy, so he accurately described the problem on the work order. The service techs replaced my rear pads and sensors and the problem appears to have been clear up. I'm not sure how long the fix lasts, but for now, my car no longer sounds like an ice cream truck or school bus as it pulls away from a stop.

[budman1]

Well, I pulled the brake sensors from the calipers and simply zip-tied them securely out of the way. I did this for the front driver side caliper and the rear passenger side caliper. No squeal anymore!

I know I could take it in for service and they will replace the pads and sensor. However, I try to avoid my service dept like the plague. Until something else crops up, my fix will do.

Simply disconnect the brake sensor from the caliper. Zip tie the loose sensor securely. You are now squeal free ... and no brake light. I will worry about knowing when to replace the pads as more miles are accumulated on the car.

[Blue330i2006]

I am sure some of our resident techs will weigh in on this, but I know from my brother who is a dealer technician that warranty works sometimes pays less than what it actually takes to do the job and certainly less than the same work done outside warranty. So on a busy day, the poor tech who is doing a warranty claim for a difficult customer (I am not pointing fingers at you here, just talking in general) is in fact losing money. My brother told me a couple of stories of his buddy techs working 8 hrs to fix a problem under warranty but the manufacturer only pays them an hour or two, so not only did they work 6 hrs for free, they may have also missed more hours because in those 6 hrs they could have sold more than 6 hrs worth of work. I just thought I'd highlight this, it is not an issue when we go in for valid reason, but maybe something to keep in mind when we go in for trivial stuff, and again I am not saying the issue is here trivial or not.


My family owns a garage, Well Said!!!!