I have recently started hearing a winding/whining noise coming from the engine compartment. The noise starts out as a low rumble and increases in pitch the faster I go. It starts at around 30MPH and continues up to and beyond 70MPH. It only goes away again under 30MPH. It only happens when the car is moving. It happens when the car is in neutral and it even happens when the engine is off and I'm coasting down a hill.

I don't feel anything unusual in the steering, acceleration, braking, or suspension. I'm thinking it might have something to do with the fan.

Any advice would be greatly appreciated.
Thanks
Russ

 

Based on your description I would guess wheel bearings or perhaps you need new brake pads?

 

Defiantly sound like a wheel bearing hub.
Rear
1998-2002 Volvo C70 Coupe Rear Wheel Hub
Front
1998-2002 Volvo C70 Coupe Front Wheel Hub