[cmyk]

A few weeks ago I started noticing a very intermittent high-pitched hum at speeds <40mph. The noise doesn't change in pitch or volume with wheel speed or engine speed, and so far I have not been able to faithfully replicate it at all -- it just comes and goes when it pleases. All weather conditions, all road conditions, etc. It seems it's mostly noticeable from the driver's seat, since passengers have not been able to hear it until I call their attention to it and they are specifically listening for it.

Tires are fairly new (~3,500 miles) and in good condition. I thought possibly wheel bearing, but in my experience those have made a "whir whir whir" noise, rather than a constant metallic hum (best way I can describe the noise). No vibrations, no other noises, etc.

Any guesses? I searched but couldn't find anyone with an issue that matched this.

[E90Company]

I think I may have a similar issue, and I have found it to be the power steering pump mounted on the drivers side. Start your car at idle, pop open your hood, and reach in and turn your wheel just a little. Do you hear a hum??? This is when I notice it mostly but I am not sure if this is an issue or not. I also hear it driving at low speeds when there isn't wind noise.

[Chris@codemybimmer]

i get a high pitch that comes and goes at random too
but i think mine comes from the center console somewhere behind the lock button area
it does get quite annoying at times...

[cmyk]

Originally Posted by E90Company

I think I may have a similar issue, and I have found it to be the power steering pump mounted on the drivers side. Start your car at idle, pop open your hood, and reach in and turn your wheel just a little. Do you hear a hum??? This is when I notice it mostly but I am not sure if this is an issue or not. I also hear it driving at low speeds when there isn't wind noise.

You might be onto something. I heard it once tonight for 5-10 seconds and it did seem to start when turning the wheel (although I've heard it plenty of times while driving straight, too). It does almost sound like some sort of electrical noise, almost like the sound your ears make when they're ringing, but much quieter and more muffled.

Anyway, glad I'm not the only one hearing weird alien sounds coming out of my car. I haven't brought it up to the dealer since I've never been able to reproduce it. Sigh...

[cmyk]

Originally Posted by 1lyfe

i get a high pitch that comes and goes at random too
but i think mine comes from the center console somewhere behind the lock button area
it does get quite annoying at times...

I recently had that area of my dash partially taken apart and there is not much back there behind that area. Could your sound be coming through your AC vents?