[Lazarus.Bird]

So I've got a '15 335i M Sport with most options. This is my first winter with the car. If the car has been sitting for a few hours (even when garaged at my house), the brakes unleash an ungodly squeal when initially driving. After I give the car a good couple of brake pumps, the noise mostly goes away. Sometimes there sounds like a very small amount of rubbing, but it is mainly brake squeal.

The noise is the worst when it is cold outside and the roads have been salted. It also happens sometimes when the temperature is moderate but it has rained.

This is my first performance vehicle and first BMW. Is this just something normal you have to deal with when you have performance brakes? My wife took the car out on errands last night and I listened to her back out of the driveway while I was standing in the house, and it sounded like someone was murdering a cat.

I've had it in to my local dealer twice to look at the brakes. The first time they found the RR backing plate rubbing and adjusted it.

The second time in I was experiencing a grinding noise when releasing the brakes from a dead stop. They removed and cleaned all pads with 80 grit and it seemed to help.

But with the snow this week, the brake squeal is back to being terrible. I'm still under warranty/maintenance package so I have no issues taking it back to the dealer. I'm just wondering if this is something I should expect to put up with, or if it is something they should be able to fix? When the weather is dry the brakes sound great. Thanks for any input.

[lethbridge]

That sounds like an issue I have had and is fairly well known on F3X models - i.e. you release the parking brake and it squeals for say 20 yards and is then fine (pumping the foot brake will make no difference in reality although you will think it does as it will clear up by itself in 20 yards or so). Obviously if it is that issue it will only come from the rear of the car and you will have been using the parking brake! I believe it is caused by a build up of dirt in the release mechanism/cables on the parking brake and just needs cleaning under warranty.

If it is not parking brake related it could be rust on discs/rotors from sitting when damp which obviously goes once you use them and is normal but that is usual a scraping noise & not a squeal. If you have the M Sport Brakes (Blue 4 pot Brembos) then they are racing brakes which are prone to squeal and is considered normal (although I have them and have never had the issue). If you don't have these brakes (usually an option regardless of whether your car is M Sport spec) then there is no excuse for having squealing brakes. Other causes can be stones flicked in between the shield and brake or worse corrosion on rotors to the point they are best replaced...

Regardless no decent car should be squealing in my view (race brakes or not) and there is usually a fix which may include shims/copper grease etc. Definitely something for your dealer to sort for you...

[Lazarus.Bird]

Thanks for the feedback lethbridge. I rarely use the parking brake. And sorry I was not more clear. I have the M Sport model, but do not have the M Sport Brakes.

I'll have to take the car back into the dealer and have them take another look. I'm fine with a little noise, but they can be pretty awful.

[Billfitz]

My brakes have never made a peep. However:
http://f30.bimmerpost.com/forums/sho....php?t=1471617

[not.ramos]

Upgrade your brake pads especially if you live in a colder area. Do your research and find the right brakes as some are really good only if you heat them up, other give good initial bite in the cold.

[SkylineGT]

I have the same problem, might be just the pads