humming vibration while creeping with brakes applied

whitenblue · 05-12-2022, 03:07 PM

I have a persistent noise coming from my 2017 X3 35i. The same noise can be predictably repeated under two conditions. One, while coming to a stop and with light brake pedal pressure, the last rolling foot or so will produce a low frequency humming or vibration almost like a rumble. Two, the same noise happens while creeping along with light brake pedal pressure and the car is barely rolling. It feels as if the brake pads are grabbing and releasing, in a pulsating "stiction" type of condition. I replaced the brake pads and reconditioned the rotor surfaces with a flat hard block and light sandpaper to deglaze them. Same sound persists.

The only thing I can think of is there is some play somewhere, like the suspension bushings, or in the brake calipers, which causes the pads to momentarily grab and release. Or maybe the bushings allow the suspension arms to deflect until they wind up then snap back causing the brake pads move relative to the rotor.

Any thoughts, ideas, or prior experience with the same?

Wgosma · 05-12-2022, 03:50 PM

Perhaps have a 2nd person positioned outside the car as you operate at low speed with the light brake pressure, see if the observer can confirm that sound is coming from the brakes.

If not, may be possible it's a driveline/drivetrain issue, or perhaps suspension component.

How many miles on the car?
Ever changed tranny and/or transfer case fluids?

05-12-2022, 03:07 PM	#1
whitenblue New Member 2 Rep 23 Posts Drives: BMW X3 xDrive35i Join Date: Mar 2020 Location: Philadelphia iTrader: (0)	humming vibration while creeping with brakes applied I have a persistent noise coming from my 2017 X3 35i. The same noise can be predictably repeated under two conditions. One, while coming to a stop and with light brake pedal pressure, the last rolling foot or so will produce a low frequency humming or vibration almost like a rumble. Two, the same noise happens while creeping along with light brake pedal pressure and the car is barely rolling. It feels as if the brake pads are grabbing and releasing, in a pulsating "stiction" type of condition. I replaced the brake pads and reconditioned the rotor surfaces with a flat hard block and light sandpaper to deglaze them. Same sound persists. The only thing I can think of is there is some play somewhere, like the suspension bushings, or in the brake calipers, which causes the pads to momentarily grab and release. Or maybe the bushings allow the suspension arms to deflect until they wind up then snap back causing the brake pads move relative to the rotor. Any thoughts, ideas, or prior experience with the same?
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05-12-2022, 03:50 PM	#2
Wgosma Lieutenant Colonel 806 Rep 1,906 Posts Drives: 2012 F25 X3 28i (N52) Join Date: Sep 2018 Location: Northern Nevada iTrader: (0)	Perhaps have a 2nd person positioned outside the car as you operate at low speed with the light brake pressure, see if the observer can confirm that sound is coming from the brakes. If not, may be possible it's a driveline/drivetrain issue, or perhaps suspension component. How many miles on the car? Ever changed tranny and/or transfer case fluids?
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