OK I've done some searching on the site but most people talk about a rhythmic whine where as mine sounds like a distant jet engine when the plane is taxiing, a very low level, smooth constant whine. My main concerns are turbo or transfer case but i have no other symptoms so I might be panicking over nothing....any idea

 

If it doesn't vary with speed and throttle position, I'm going to throw my guess at the electric radiator fans. Could be a bearing. Can you hear it when you pop the hood and standing over the engine compartment with the engine running?

 

I'm pretty certain now that it's a turbo whine. I notice it most when starting from cold, it's been 25-30 degrees in the early morning . As the engine warms up it gets less and less until it's almost gone. I suspect that its a lubrication problem that kinda scares me. As the oil gets warm and thins out it seems to lubricate the turbo assembly more efficiently. The oil and filter was changed about 3,000 miles ago according to records when I purchased the car, perhaps its time for another oil change with known products. The oil level is correct on the dip stick.

 

Could also be the turbo coolant pump. Did you get the recall performed on that?

 

Just had it replaced last week under the recall.