[chewable]

Hey guys,

I've noticed that my 2011 e90 has this chirping sound about 75% of the time when braking. It also doesn't make the sound reliably during the entire time I'm braking, probably once I slow past down to 10 to 5 mph. It doesn't happen if I'm not braking and is worse if i brake hard.

This is a video of it: https://photos.app.goo.gl/f6Wsz2odQYLThsFB9
Its a little hard to hear in the video but it is louder in person

I've been reading around and some have suggested it was brakes without anti-squeal paste, so I changed my brakes today but still squeals. Others have suggested it had to do with the hand brake, but the sounds are coming from my front, not rear. Others have suggested its my drive belt or front crankcase seal, but why would it only happen when braking? I'm not sure but it is very annoying. I'd appreciate any insight in where to begin diagnosis.

[chewable]

Can anyone help me?

[Emilime75]

That's the car telling you to activate your turn signal BEFORE you get to the turning lane and come to a complete stop.

[e91Owner]

Originally Posted by chewable

Hey guys,

I've noticed that my 2011 e90 has this chirping sound about 75% of the time when braking. It also doesn't make the sound reliably during the entire time I'm braking, probably once I slow past down to 10 to 5 mph. It doesn't happen if I'm not braking and is worse if i brake hard.

This is a video of it: https://photos.app.goo.gl/f6Wsz2odQYLThsFB9
Its a little hard to hear in the video but it is louder in person

I've been reading around and some have suggested it was brakes without anti-squeal paste, so I changed my brakes today but still squeals. Others have suggested it had to do with the hand brake, but the sounds are coming from my front, not rear. Others have suggested its my drive belt or front crankcase seal, but why would it only happen when braking? I'm not sure but it is very annoying. I'd appreciate any insight in where to begin diagnosis.

It does sound like a tensioner or belt squeal. If you haven't replaced yours... it's certainly easy and not that expensive. But this is just a throwing parts at your car solution.

[chewable]

Originally Posted by e91Owner

It does sound like a tensioner or belt squeal. If you haven't replaced yours... it's certainly easy and not that expensive. But this is just a throwing parts at your car solution.

i have the parts on the way and will try that. but wouldn't you expect the squeal to occur at all times? not just when i'm braking?

[cliffschum]

I'd spray the belt with conditioner first, before replacing. Lubricate the tensioner too.

[Jurciks]

Try to turn off A/C (heater) and then try to brake.

[chewable]

Originally Posted by cliffschum

I'd spray the belt with conditioner first, before replacing. Lubricate the tensioner too.

Ill try spraying the belt down first. It looks in good condition but has not been replaced at 87000 miles so will try and report back. Ill likely replace it anyway since its due.

Originally Posted by Jurciks

Try to turn off A/C (heater) and then try to brake.

It happens whether or not the ac/heater is on.

[e91Owner]

Originally Posted by chewable

i have the parts on the way and will try that. but wouldn't you expect the squeal to occur at all times? not just when i'm braking?

Can't really explain that since the brakes boost from vacuum like most cars. I'm just commenting on the sound. It could be that since the engine is also decelerating when you are braking that they just happen to be coincidental. Have you tried revving the engine in neutral to see if the sounds follow?

[Jurciks]

I have a similar sound when braking, but it disappears when i turn my A/C (heater) off.