I just moved up north, where it is in the high 30's, and now whenever i start my car, it makes a bad whining noise, accompanied by grinding when I turn the steering wheel. I drove it around for about 20 minutes yesterday, and it didn't go away. It is a 2000 A6 Quattro 4.2L, 94000 miles.
Not so sure about the grinding when you turn, but the whirring noise is most likely your idle speed control motor reacting to the extremely cold temperatures. They are known to whine in cold temps.
I like the answer above, but don't rule out power steering pump either...
ya i was going to say its probably your power steering motor
Looking for a Used A6 in your area?
CarGurus has 7,101 nationwide A6 listings starting at $1,800.
Search Audi A6 Questions
Audi A6 Experts
Related Models For Sale
Used Cars For Sale