[Bmwguy11]

We have a 2007 X3 3.0si with about 75,000 miles on it. We bought it used 2 years ago so I don't know much of the service history on it. Today I noticed there is a whining sound coming from the front/engine bay. It goes up/down with rpm, and disappears once you get over about 2500 rpm. It's a mechanical whining/whirring is about the best I can describe it.

It sounds very much like the whine in this video:

I know it's impossible to make a diagnosis with just that info, but I was hoping ideas or possibilities could be offered. Or if anyone has had anything similar?

[Mark M]

Not sure as to the exact nature of your whining sound. However my 2005 X3 3.0 has a noticiable audible pump sound. The sound of the hydraulic power steering pump. It has had this sound as long as I can remember. However it is surprising, prior to this I had a 2002 325xi (almost the same engine) with no pump sound. My father had a 2002 530i (same engine) also with no pump sound.

Not sure what it is...but it runs fine.

Side note, if your whine is more like the sound of air rushing, check your intake boot. They are FAMOUS for tearing on the lower elbow that feeds the idle control valve. Mine was torn at 88k miles but was an easy fix. It was also torn on my prior 325xi too.

[JDAURIA]

I've listen to the video a couple times and don't notice anything out of the ordinary. Was this after a cold start? I know my e46 makes a whining noise on cold starts until the engine warms up, and then dissipates.

To add to Mark M. my e83 does have a very noticiable steering pump sound when turning at low speed. My e46 does not make this noise, but I believe my fathers e70 x5 does. Must be something post 2006???

And to add to check the lower intake boot. I have a picture of what mine looked like when my e46 was throwing CEL and whining. Ill post when I find the picture on photobucket. You can check by simply feeling along the intake boot.