[cspinnnn]

Hey everyone,

I'm having an issue with my F30, for the most longest time I've had this constant squeak coming from the rear. It sounds like it's coming from the rear passenger side.

Basically, the squeak is constant as I'm driving but fades away when I get up up highway speeds. As I'm slowing down/coming to a complete stop, the squeak converts into more of a running noise.

It's a little hard to explain but you'll understand if you watch the video attached below.

I've brought it to BMW 3 times, first time they said it was brake pads/rotors so i replaced them all(front too) & it was still there. Second time they said some bushings were dry so we lubed them up & nothing changed. The last time they recommended a full brake service, they readjusted my parking brake, lubed everything up,cleaned up the brake pads/rotors & it finally went away…For 2 days

They checked the calipers & they seem fine & there's no uneven tread wear.

I've kinda lost faith in making this squeak stop, so I'm hoping somebody in this forum has encountered the same issue & has a fix.

Please let me know!

*video link below*
https://youtube.com/shorts/n_mJVok2158?feature=share

[dmaxdmax]

I wonder if you have a slight amount of runout...where you have a slight angle between pads and rotor so the pad is touching the rotor each rotation lightly. At slow speeds, it's 'playing' the rotor like a wet finger on a wine glass...sort of thing.

Often it's because it's not perfectly flat between wheel, rotor, and hub. You could yourself take things off, clean them up, tighten them up and pray.

For a test of this theory, go on the highway for 15 mins. or so and try to pull over without using your brakes...then touch the rotors through your wheels with a wet finger to see if one is noticeably hotter than the others.

You may also have a slightly sticking caliper (which would heat up the inside edge of rotor first...you can touch the top through the wheel too (maybe?)

Especially since they put new pads/rotors, your piston will be back inside the caliper where it had been further out before--they'll get a ring of rust which can stick on the calipers sealing ring.

Pistons can be removed and cleaned up with fine sandpaper. I suspect they're pricey calipers so if you want to save money, I'd look for a complete rebuild kit...take it to a shop if you're not comfortable DIYing and don't want to die.

[Billfitz]

The way to find out what's happening is to get the wheels off the ground and do some low speed 'driving' and braking. If the noise is there the problem is somewhere in the drive train and/or brakes, at which point you'd want to get the car up on a lift to repeat the process with someone under the car to pinpoint the source. If the noise isn't there doing that test it's somewhere in the suspension or something underneath is rubbing. You test that by pushing down on and releasing the rear of the car to get it rocking.

[cspinnnn]

Thanks so much for the reply! I actually have done that before & from what I can tell is the noise is still there even raised up. I was able to figure out that it really only starts after I hit 20KM/h. Its a really weird problem

[cspinnnn]

Originally Posted by dmaxdmax

I wonder if you have a slight amount of runout...where you have a slight angle between pads and rotor so the pad is touching the rotor each rotation lightly. At slow speeds, it's 'playing' the rotor like a wet finger on a wine glass...sort of thing.

Often it's because it's not perfectly flat between wheel, rotor, and hub. You could yourself take things off, clean them up, tighten them up and pray.

For a test of this theory, go on the highway for 15 mins. or so and try to pull over without using your brakes...then touch the rotors through your wheels with a wet finger to see if one is noticeably hotter than the others.

You may also have a slightly sticking caliper (which would heat up the inside edge of rotor first...you can touch the top through the wheel too (maybe?)

Especially since they put new pads/rotors, your piston will be back inside the caliper where it had been further out before--they'll get a ring of rust which can stick on the calipers sealing ring.

Pistons can be removed and cleaned up with fine sandpaper. I suspect they're pricey calipers so if you want to save money, I'd look for a complete rebuild kit...take it to a shop if you're not comfortable DIYing and don't want to die.

Thanks so much for the help! I checked the temp of the callipers after my drive into work today & it feels like there all pretty much the same temp. Ill give it a try with the caliper restoration kit.

I'll let you know if it changes anything!!

[Billfitz]

If it only does it at higher speed I'm inclined to think it's not the drive train or brakes. Anything there that's rubbing would rub at any speed.

[njdangelo]

The noise seems rotational in nature as you can hear it change rhythm slightly in the video which I can only assume is happening with a slight change in speed. If you can narrow down which wheel it is that would be a good start too. Then I would make sure all suspension components were nice and tight. Same with the caliper brackets. It's possible that it doesn't happen at low speeds because there isn't enough inertia to cause whatever is slightly lose to go lose? Maybe your wheel bearing is starting to go and so your getting some side to side vibration once you pick up speed? Just spitballing here but it seems brake related in my opinion… does it go away when you hit the brakes?

[dmaxdmax]

Originally Posted by cspinnnn

Thanks so much for the help! I checked the temp of the callipers after my drive into work today & it feels like there all pretty much the same temp. Ill give it a try with the caliper restoration kit.

I'll let you know if it changes anything!!

No need to bother if you're not noticing a temp change. You might try again on a longer drive, but if one isn't warmer, it's not a caliper issue. Look elsewhere.

[cspinnnn]

I've pretty much narrowed it down to the passenger rear wheel. There's no vibrations when driving, I shook the wheel and there's no play at all. I'll take the wheel off and make sure everything is tight over the weekend & I'll keep everyone posted!

My personal opinion is that the squeak is coming from the dust shield making contact with something. I tried pushing it back but it was still present. Maybe I take off the shield and bring it for a test drive & see.

[dmaxdmax]

Don't take the shield off...just bend it back a little firmer all the way around evenly. They seem to often get banged when wheels come off.

[QuestMCoupe]

Did you ever figure out what the noise was? I'm having a similar issue, but mine starts as soon as the car starts to move. Only does it sometimes though.

[cspinnnn]

Originally Posted by QuestMCoupe

Did you ever figure out what the noise was? I'm having a similar issue, but mine starts as soon as the car starts to move. Only does it sometimes though.

It was actually one of the rubber grommets. Just needed some lubricant

[Saito]

Originally Posted by cspinnnn

It was actually one of the rubber grommets. Just needed some lubricant

Hey man, do you mind explaining a bit more? I have a similar issue and would love to try your fix.

[quakerroatmeal]

Just coming across this thread I've had a similar noise for a while. I recently fix the common issue of the parking brake clip that holds the cables in place underneath car was broken leaving the cable hang loose. This end up being what was making squeaking noise that sounded like it was coming from the rear. Hope this helps someone.