My wife noticed a new noise a couple weeks ago and I have had two different mechanics drive and listen. Neither can pinpoint it.
It sounds like a medium pitched whirring when I reach 30 mph. It gets slightly louder as speed increases and will almost cease when I take foot off accelerator only to start back when i accelerate or give it gas to maintain speed.
It does not make a difference if I move to neutral while going down the highway and does not change with steering wheel movement. I have had tires rotated and proper PSI verified as it almost sounds like tire noise. Although there is no change in noise when there is a change in road surface.
I really think it is coming from drive train as it is clearly louder with acceleration.
Vehicle has AWD and 139K miles on it. I have searched noise from differential, transfer case and wheel bearings. Because there is no change when I turn wheels I have sort of ruled out wheel bearings. There is no clicking or anything other than the constant whirring.
both mechanics have said not to worry until it gets worse or changes sound but with Christmas travel coming up I want it to be fixed.
Thanks for help/suggestions.
