pbarch1

This last weekend, I noticed a light whirling noise inside the cabin. It almost sounds like a fan. It's very soft and can only be heard when everything else is off.
It appears to be speed related, it gets faster as I begin to accelerate, and goes away at about 15 mph. (or maybe not, but at that point I can't hear it over the engine) Any ideas?

fortysixandtwo

Possibly the front differential or a drive line bearing.

19psi

Does it do for a while after shutting down the car? If so, it's probably the amplifier fan in back.
If you're positive it's speed related, it's something else.

mitch48

Do you have seat ventilation and is it possibly activated? I have accidentally turned mine on a couple of times and soon notice a fan noise coming from the back seat area, it is always the seat vents.

deilenberger

Or if you have the 4-zone heat/AC - I've been surprised by the fan for the rear zones running, it's located in the trunk area on the port-side (behind the big vent thingie..)

pbarch1

This is just a follow up. It was the Cardan Shaft bearing. replaced under warranty.
Started out as a flutter, sounds almost like a playing card on the spokes of a bicycle.
Went on for several weeks, started to get more pronounced.
Anyway just an FYI