[3X3=5]

My car makes a very loud high pitched tone when braking at just at the last foot or so when wet. It's very annoying and happens any time after I wash my car or it's rained a bit (which is a lot in Seattle). It goes away after a dozen or so times of braking to a complete stop. Took it to the dealer who claimed they couldn't replicate the problem which of course is BS since all you have to do is hose down the wheels. This time when I go back I would like to have an idea of what the issue is (I'll also show the video). Thanks for input.

[Route 16]

That's just it, it's the water. I used to live in flooded areas. After you have those rotors and brakes swimming in water it will squeal, that is normal. Drive around and let it dry.

[3X3=5]

Obviously it's caused by the water, but I can't consider this to be normal. I've never had a car that did this before and that includes an E36 and E46. Why does this car squeal like crazy when the brakes get wet?? What can be done? Hasn't someone else out there had this issue before?

As a side note the dealer tried to blame it on my aftermarket wheels, which I find extremely unlikely.

[chaFT328i]

Seems normal enough to me. I frequently wash my car(once every 2 weeks) and I hear the same thing when I pull into the garage after. Someone correct me if I'm wrong, but I believe its got to do with the pads being wet.

[3X3=5]

So every E90 out there experiences this yet none of the other cars I've owned (or ridden in) do? It's hard to imagine that BMW somehow made the E90 brakes so unique that it's the only car I've ever seen with this issue. Maybe I'm the only one but I find it pretty annoying.

[e90pilot]

No not normal. I though you were honking at first lol! I think you (or your dealer) just need to apply antisqueal to the back of the pad.

[3X3=5]

Thank you - the first person to say this isn't normal. OK, anti-squeal, seems simple. Anyone else had an issue like this and have any insight?

[3X3=5]

Bump - anyone else? The lack of replies indicates to me that not many people have experienced this, thereby confirming it's not normal. But what's causing it? So far one vote for anti-squeal on the back of the pads. Any other ideas??

[mike-y]

lol, I just watched the video. While I think some noise is normal, because it happens to me sometimes at low speeds (HPS pads though). But it's not nearly like your car - *that* noise is comically loud, and not what I'd consider normal. Also, the parking structure may be amplifying it.

you can try more ani-squeel, like e90pilot suggested.

[SG_E92]

Have the same exact sounds, pisses me the fck off!!! The best is when i have people in my car and they hear it and tell me, "time for some new brakes" even tho all my pads and rotors are <7,000 miles old replaced under BMW extended maintenance plan. As far as Im concerned its absolutely not normal, didn't even bother with my dealership bc i just know how they are and they will dismiss it and it will just be a waste of my time. Let me know if you find some way to resolve it!

[3X3=5]

The garage doesn't amplify the noise - it's as bad as it sounds. The other day I was parked on the street and it had rained a bit on the drive there, when I left it did this and my friend was like "is someone honking?" It's embarrassing how bad it is. I'm still under warranty and had the dealer claim to not be able to replicate the problem once, but I'll be going back in and showing the video to demonstrate. Since they tend to dismiss any and all problems as "normal" I like to have an idea of what the issue is before I go in. That's why all suggestions are appreciated.

[mosx]

I always had brake squeal on my 135i, everyone told me it was normal for Brembo's. Now that I have the 335 I never get brake squeal. Wet/dry/hot/cold. So I'd say it's not normal. Have you replaced the pads recently? Were they bedded in? Maybe there is something on the rotor itself, maybe do some brake stands from 50-60mph?

[3X3=5]

The pads were replaced at the dealer in June when I went in for this squealing issue. Although they blamed the squeal on my aftermarket wheels, they also noted "found brake sensors are squeaking front and rear. Replaced pads and wear sensors." No idea if they were bedded in (or what that means) but I would assume the dealer did it correctly. However there was no change in the noise, it resumed the next time it rained.

Like I mentioned in my original post, the noise does go away after hitting the brakes about a dozen times. What I'll usually do after washing the car is drive a couple hundred feet with both the gas and the brake applied. That solves it, so it seems like maybe it's rust that builds up on the brakes or on the wear sensor and that's why I can burn it off with this method. I've read about the wear sensors causing a squeal noise - can anyone confirm this is what it sounds like?

[zerep1]

pads are wet if you got from 60 to 20 quickly enough you should be able to dry them off

[3X3=5]

Originally Posted by zerep1

pads are wet if you got from 60 to 20 quickly enough you should be able to dry them off

Again, not looking for temporary fixes but reasons this is happening in the first place.

[Express]

did you try anti squeal on the pads and putting some lube on the caliber bolts?

[hipnotic]

first time i ever heard it that loud. But i assume it is the water

[3X3=5]

Originally Posted by express705

did you try anti squeal on the pads and putting some lube on the caliber bolts?

Haven't tried anything yet (since the first dealer visit). Looking for suggestions of what could be the cause for when I go back in. Lube on the caliper bolts, I'll add that to the list, thanks.

[3X3=5]

Originally Posted by josh06lau

first time i ever heard it that loud. But i assume it is the water

Yes, as we've well established it's caused by water, said that in my original post. But water should not cause this so that's what I'm trying to answer.

[zerep1]

i understand you have established this and your previous cars dont do it but something that comes only when its wet and goes away when it isnt is water i mean i does sound loud but i dont think its you brakes failing
do you get the brake whistle when driving slow
does it happen when its cold out side warm out side do you get an vibrations or pull from the brakes when you slow down

[3X3=5]

I never felt like the brakes were failing, they work fine. I do not experience any noise in any other situation than post-rain or car wash. Seems to happen at any temperature. No vibration when braking. Like I mentioned they were checked at the dealer in June (car only has 40K mi) so I don't think there's a failure issue.

Still wondering if it's a problem with the brake wear sensor. Anyone?

[Express]

Originally Posted by 3times3

Haven't tried anything yet (since the first dealer visit). Looking for suggestions of what could be the cause for when I go back in. Lube on the caliper bolts, I'll add that to the list, thanks.

no problem. you arent going to find much else other than that.

brakes are simple. there could be some foreign material somewhere stuck on the pad causing the noise too.

i can tell you for sure- its not your wheels hahahah