The MINI with neverending issues... (2008 Cooper S w/ dealer-installed JCW kit [chip tune, bigger intake, bigger exhaust])
Recently I've noticed a whirring or whistling noise above 30mph. It does not happen under that speed (or at least is inaudible), and the pitch of the noise does not change with vehicle speed or engine speed. It also does not change if I turn left or right, so it doesn't seem to be suspension-related.
Any ideas? If I had to guess, I'd say it was coming from somewhere close to the firewall near the center, but it's very hard to pinpoint.
Car performance is unchanged, no CEL.
Update: The noise is definitely coming from under the hood in front of the driver seat. It gets louder the faster I go, but does not change in pitch. It does not appear to be related to suspension or tires, as sharp turns at speed do not affect it. Here is a photo of under-the-hood http://www.eurocarnews.com/media/pictorials/1654/8417.jpg There's not a whole lot there...
Update 2 I realized what the noise reminds me of. It sounds like air blowing over the top of a straw. A really breathy whistle.
Update 3 More troubleshooting steps: I've shifted into neutral and let the engine come down to idle and the noise is unchanged. I've tried activating the windshield wipers, no change. I've brought the engine to 2k rpm while not moving, and the noise does not occur. I've driven with my head out the window and cannot hear the noise over the wind.
Update 4 It may be imagination, but it might be getting louder?
Things I've noticed: 1. The noise GOES AWAY when I turn the steering wheel in either direction. The power steering pump in this car is electric, not belt driven. 2. It is much louder at highway speeds, but is noticeable even under 30mph (just very quiet). The noise disappears under 5-10mph.
I put the car up on ramps and gave everything a good lookover. Aside from dirty oil residue all over the transmission (I'll have to track down where that leak is coming from...probably the filter housing), everything is in good shape. One of the accessory pulleys is a bit squeaky. I couldn't tell if the squeak was from the alternator or the water pump (they're right next to each other).
I didn't see anything that looked out of place and nothing was loose.