[Yanray]

Originally Posted by freesole

Did you happen to get any further info on what kind of software update was done? It sounds like there would be a few others here that would like to have the same applied haha

I’ve reached out to my service advisor for more information. I’ll let you know when I hear back.

[Savage_M3]

Originally Posted by Yanray

I’ve reached out to my service advisor for more information. I’ll let you know when I hear back.

Thanks! Any info or TSB that they can reference would be helpful for my next service!

[///M-Life]

Happens in heavy rain as well, not just snow

[JDS]

I've had it too here in the UK when driving on the motorway in cold wet conditions (I know, not the UK right )
Really freaked me out, so if there are any updates on what was changed to the car above, I'd certainly be interested.

[thatguyfromthatshow]

Yeah, this happened to me as well. It was raining, I was on the highway, hit the brakes and a big swerve/pull to the right. It happened 3 times in a relatively short trip.

On the way home, in still rainy and cold weather, it didn't do it. So I thought that there was something on the disks that had been rubbed off on my way to the place I was going. Now I know that it may be a thing. I will also bring it up with the dealer.

[DBU]

So, ten years ago, the "cutting edge technology" was that brake drying would take place when, and ONLY when, the wipers were engaged in either normal or fast mode. I mostly run the wipers in intermittent or "auto" mode. Unless the technology has changed, I don't get automatic brake drying.


And for you folks reporting this phenomenon, you really need to also report exactly how the wipers were running at the time.

[Savage_M3]

Happened again last night in rainy weather. Wipers were clearly on.

Initial brake engagement is weak at best for the initial bite and then it seems to come alive after a half second or so. Not linear at all, very much like a step function in braking force. A bit unnerving when you're driving and trying to manage your braking distances in inclement weather.

Never experienced this on any other car in the rain, including my M3.

Any luck with a TSB I can reference? I can already hear my advisor telling me this is normal in bad weather.

[JB20DGM]

Originally Posted by Savage_M3

Happened again last night in rainy weather. Wipers were clearly on.

Initial brake engagement is weak at best for the initial bite and then it seems to come alive after a half second or so. Not linear at all, very much like a step function in braking force. A bit unnerving when you're driving and trying to manage your braking distances in inclement weather.

Never experienced this on any other car in the rain, including my M3.

Any luck with a TSB I can reference? I can already hear my advisor telling me this is normal in bad weather.

I don't think anyone here that brought it up with a dealer has seen any kind of TSB about it.

Were you in "Auto" mode or did you manually select one of the continuous operation levels (i.e. low/high)?

[tm811]

Might be an LCI thing?
I have a pre-LCI driven in very harsh conditions (-34 celcius, freezing rain, heavy slush) without issues.

[lagunablue1]

Originally Posted by tm811

Might be an LCI thing?
I have a pre-LCI driven in very harsh conditions (-34 celcius, freezing rain, heavy slush) without issues.

Still have the same issue with my pre-LCI. Was just driving up to the cottage in the rain on Saturday, it was +4 and the super weak initial bit persists.

I'm wondering if switching to another pad compound (i.e. the Isweeps) might help.

[tm811]

Originally Posted by lagunablue1

Still have the same issue with my pre-LCI. Was just driving up to the cottage in the rain on Saturday, it was +4 and the super weak initial bit persists.

I'm wondering if switching to another pad compound (i.e. the Isweeps) might help.

Interesting - I think that would be the next logical step to try. Hope it works out

[Savage_M3]

Originally Posted by JB20DGM

I don't think anyone here that brought it up with a dealer has seen any kind of TSB about it.

Were you in "Auto" mode or did you manually select one of the continuous operation levels (i.e. low/high)?

Auto Mode on the wipers.

With regard to the TSB, was hoping someone might have come across something. Makes life easier when working with the dealer on a odd issue like this.

[JB20DGM]

Originally Posted by Savage_M3

Auto Mode on the wipers.

With regard to the TSB, was hoping someone might have come across something. Makes life easier when working with the dealer on a odd issue like this.

I wonder if being in auto mode won't trigger the brake drying and it requires manually being in one of the continuous operation modes.

[Savage_M3]

Originally Posted by JB20DGM

I wonder if being in auto mode won't trigger the brake drying and it requires manually being in one of the continuous operation modes.

I'll try that out. My M3 has auto wipers and I never noticed this type of braking issue. Then again, it's a 2011 so maybe the brake drying was handled differently if at all.

[lagunablue1]

Originally Posted by JB20DGM

I wonder if being in auto mode won't trigger the brake drying and it requires manually being in one of the continuous operation modes.

I was stuck in about an hour of heavy downpour this weekend and had a chance to test this out.

At first (temp was 10C/50F), it seemed to make a bit of a difference. But once the temps dipped to 7C/44F, it was back to like an inch of travel at the top where the brakes did nothing, and then all of a sudden a TON of braking force. It's like the pedal turns into an on/off switch until you activate them a few times, regardless of whether the wipers are on auto or continuous.

I really think it's just a result of the pad compound/vented rotors and the amount of brake ducting. Clearly, with a heavy amount of precipitation below a certain temp, the brakes just over-cool and you can't keep them in the optimal temperature window on the highway.

[Golf_GL]

Now that its winter again with wet snow and rain, I am seeing this happen every time, even with wipers in Auto. I brake early before the ramp to work off the buildup like others have mentioned, and then apply the brakes again. I can even tell that when regaining braking, each wheel takes up at different times, so the car gets a bit squirrelly under high speed braking. Quite dangerous, I've never had it this bad on any of my other cars.

For the M3/M4, I believe the manual states to remove the brake vent cover in the wheel well for track use but replace for regular driving. I wonder if it is the same vent that is allowing so much water/slush into the brakes at speed. Linked below for reference, its not quite the same discussion though.

https://g80.bimmerpost.com/forums/sh....php?t=1848974

[strohw]

Originally Posted by Golf_GL

Now that its winter again with wet snow and rain, I am seeing this happen every time, even with wipers in Auto. I brake early before the ramp to work off the buildup like others have mentioned, and then apply the brakes again. I can even tell that when regaining braking, each wheel takes up at different times, so the car gets a bit squirrelly under high speed braking. Quite dangerous, I've never had it this bad on any of my other cars.

For the M3/M4, I believe the manual states to remove the brake vent cover in the wheel well for track use but replace for regular driving. I wonder if it is the same vent that is allowing so much water/slush into the brakes at speed. Linked below for reference, its not quite the same discussion though.

https://g80.bimmerpost.com/forums/sh....php?t=1848974

Try a ceramic pad, it may help a bit. It's a bit of a combination of them both from my personal experience. The OEM brake setup on my BW was worse in regards to weak braking when the brakes were wet than my X3M. I ran ceramic pads in the winter and it helped some.

[Bimma360]

I haven't experienced this in the X3M in the few times I have driven in the rain, but I have only had it for 3 months now.

Just to add another data point here though... This first and only time I have ever experienced these exact symptoms was on my e36 M3 almost 10 years ago. It was a rotor issue. I can't remember what the exact term was, but essentially the rotors were glazed or something along those lines. During infrequent use of the brakes in wet conditions (like driving on the highway), the car had zero brakes for the first second of pressing the brake pedal. Once the that initial brake press dried off the rotors the car started to stop. Yes very scary, and not normal at all. Prior to that, I have never driven a car that did that or has done that ever since. I didn't even know that was a thing. The brake drying feature on these modern cars is nice, but I highly doubt its lack of function would yield this affect to the degree everyone is describing.

I am betting the rotors and/or pads are toast. Replacing those is most likely the fix. At least that is what I would do.

[Golf_GL]

Originally Posted by Bimma360

I haven't experienced this in the X3M in the few times I have driven in the rain, but I have only had it for 3 months now.

Just to add another data point here though... This first and only time I have ever experienced these exact symptoms was on my e36 M3 almost 10 years ago. It was a rotor issue. I can't remember what the exact term was, but essentially the rotors were glazed or something along those lines. During infrequent use of the brakes in wet conditions (like driving on the highway), the car had zero brakes for the first second of pressing the brake pedal. Once the that initial brake press dried off the rotors the car started to stop. Yes very scary, and not normal at all. Prior to that, I have never driven a car that did that or has done that ever since. I didn't even know that was a thing. The brake drying feature on these modern cars is nice, but I highly doubt its lack of function would yield this affect to the degree everyone is describing.

I am betting the rotors and/or pads are toast. Replacing those is most likely the fix. At least that is what I would do.

You make great points. The thing is, my car is exactly an year old today, and I experienced the braking issue last winter too when the pads and rotors were brand spanking new! I wonder if they added an alternate manufacturer recently and that's causing the issue.

[JDS]

I also posted on this thread around March this year, after noticing the same phenomenon with my LCI X3M. At the time, I thought it was due to the combination of motorway driving and the wet.

I have since driven in a lot of wet conditions over the course of the summer (it is the UK!), and have never had this issue present itself since, when using auto wipers or full manual on.

Unitl now. We have just had some cold weather here, and the issue is back. It even caught my wife out when she was driving us home the other night.

So I am now convinced this is a temperature/rain thing, exacerbated by motorway driving, that is allowing the brake compounds to drop in temperature much more than we would see when driving around town.

[Bimma360]

Originally Posted by Golf_GL

You make great points. The thing is, my car is exactly an year old today, and I experienced the braking issue last winter too when the pads and rotors were brand spanking new! I wonder if they added an alternate manufacturer recently and that's causing the issue.

Yeah I am sure that is frustrating. It is always possible that the parts were defective from new. It does happen.