Ok, I'm pretty sure that it is my wheel bearings, after all it was 10k miles that they were replaced. When I'm driving I get a whirring sound, like someone is blowing in a bottle. It changes pitch with speeds and is loudest at 25-30mph, and 45-50 mph. If I turn off the car it is still there. Sound like em? If I buy the new hub assemblies are the bearings already pressed in? Thanks.