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On my 2005 BMW 320D, I recently (200 miles/1 month ago) noticed a rubbing noise coming from the front passenger side wheel. It is only really noticeable on smooth tarmac at slow speeds, but I did notice some slight "rubbing" noise on the motorway also.

I jacked up the car and spun the wheel, where I could hear the rubbing at a certain point each time the wheel spun. I could only manage about 2 revolutions of the wheel because of how tight it is at that point. I checked the other side and it spins much more freely. Then I removed the wheel and rotated the disc by hand and same as above it is tight at one certain point.

In order of what I think is the most logical reason for this given the symptoms:

  1. The disc is warped
  2. Something else ?
  3. The caliper
  4. The brake pads

The pads were replaced about 3000 miles ago and look to have plenty left on them. I haven't noticed any judder when braking. Nothing has been altered on the car in the lead up to when I noticed this noise.

Can anyone shed some light on the cause of this? Thanks.

Some further info I just thought of:

The noise is noticeable in any direction the wheels are pointing when moving(IE not just when turning left etc)

The brakes are now squealing, but only seems to happen when braking lightly at slow speed.

After looking at/listening to some youtube videos of wheel bearings gone bad, I'm pretty sure that it's not that.

Also I noticed when reversing the other day without any braking, the brakes(or something?) were squealing.

The brake pad is definitely tight to the disc at one point, maybe for about 1/8th of the circumference of the disc.

  • While driving does the wheel in question get hot? It's a good sign the caliper is bad. If you open the bleeder valve does the wheel spin freely? – Ben Apr 15 '16 at 0:17
  • Sounds kind of like a bad wheel bearing. – rpmerf Apr 15 '16 at 12:31
  • @Ben I'm not sure what the bleeder valve is? And do you mean if I drive as normal (including normal braking), does the wheel get hotter than the others? I will check this. Also I've added more information to the original post. – cdsln Apr 15 '16 at 19:18
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    This is on a different car but it's what you're looking for. pelicanparts.com/catalog/wizards/BMW_E30_Brake_Wizard/… – Ben Apr 15 '16 at 20:43
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My first guess would be a warped or marred rotor. By "marred" I mean a section of the surface has been corrupted by a corrosive or partly glazed, so that it is smoother or rougher than the rest of the rotor. Both of these can be diagnosed by the same treatment. Have the rotor "turned" (almost any auto parts or machine shop should do it for less than $30). If it's warped, it should become obvious while they're turning it, and a competent shop will tell you about it. If the surface was corrupted, it'll get scraped off, but you might never know what it was.

Either way, you'll be good to go, at least for a while.

In either case, something caused the problem. Hopefully, it was a one-time deal that won't happen again. In my case, it was an improperly installed brake caliper, so even when I got the rotor straightened out, the caliper just warped it again. It'd be good to check it out and see if you can figure out what caused the problem in the first place.

The best way to check if it's the brakes or the bearing is to take the rotor off and try spinning the wheel hub. Even a good bearing will have a slight resistance, but if it sticks or rattles in and out, then it's bad.

  • Following up on this - I replaced the brake disc and pads with brand new ones, and the rubbing is still there - per revolution. I guess this leaves either the caliper or something else. Since the caliper is fixed in position then I'm leaning towards something else, but I still don't know what to try next. Suggestions? Thanks – cdsln May 29 '16 at 19:57
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    Yeah, I agree with your instinct. Even in my case, the problem went away at first, until the caliper had time to warp the rotor again. It's probably not the caliper. The next thing I'd investigate is the wheel bearings. There should be good information online for how to check the wheel bearings for your car. It won't be in the user manual, but it's not hard. – Matt May 31 '16 at 13:17

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