Whurring road noise - should I be worried?

[lloydy]

Hi all!

Been searching this forum for a while and can't find anyone with exactly the same issue as I have.

I have a BMW 2003 "facelift" 318Ci.

When driving I have a deep whurring sound - it sounds very similar to a tube or subway train copping to a stop at a station!. It is wheel rotation noise and not engine noise as the sound is there regardless of RPM etc. It is especially loud when braking. I always thought it was tyre noise but it is surely too loud to be that. I have plenty of tread left on the tyres and they are all at the correct pressure so I don't think it's that. They are Dunlop types (not the best I know but they were on there when I bought the car).

A few things I have though it could be:
- general road noise that I shouldn't be worried about - though it is pretty loud!
- brake pads worn
- brake discs warped or worn
- reading this site: bushings?
- reading this site: front arm?
- crappy cheap tyres (and naff tread)
- wheel bearing - though I know what that sounds like when worn and this noise I'm getting is somewhat different.

Has anyone else experienced this problem or is it just me?

Thank you all in advance,

LLOYDY

[njoni007]

This noise can be from:

- A wheel bearing has gone dry (usually makes a humming noise)
- Drive shaft is unbalanced (if you have gone on e ditch or something this can be caused but it or you crossed a medium etc.)
- Missalignment
- The differential has no Oil!!! It is pretty easy to check this.
- Suspension system (i.e. the coil has come out of the seatting or it does not have the rubber seatting)
- A tire has been worn unevenly i.e. it was locked when you applied your brakes at some high speed (makes a humming noise too)
- Check the oil of your gear box (if it is Manual)

But please provide some more details about the noise. Like at what speed is noticable, when it started was there any abuse that you did (i.e. 360 deg spin :D ), what does it sound like exactly and where it seems to come from (front, rear, left right, middle etc.)

[Fingers]

2001 BMW 330i with sports package...

Just changed the brake pads on front and rear and the rotors seemed fine (no grooves or warpage that I could see) and all seemed well. (although i had some issues replacing the brake pad sensor... broke the fit on the front one so i have to buy ANOTHER one and replace it... anyone have any advice for replacing them without braking them) but a hundred miles or so after changing brakepads there is a loud grinding noise while braking, and even after accelerating there is still a slight grind noise as if the brake pads are still kinda stuck on the pad.

After I had replaced my brake pads I had painted my calipers red so I was wondering if that is a possibility? If so what can I do to check that? It doesn't sound like wheel bearings because I know how that goes because of a 4Runner I used to own had bearing problems every 6 months.

Also thought the problem could be rotors and was wondering if I should have them turned. But the only thought on that is that the sound is constant, usually if rotors are warped there is more of a rythm in the grinding. The noise is loudest at about 15 mph when I'm doing the most braking.