Originally Posted by mccorry
Mine does it in a straight line... not while turning, Blue.... at 40MPH at 5000 RPM. The tires aren't spinning.
IMHO, It is a harmoic vibration that is coming through the floorboard... either a bushing that is less pliable at colder temperatures... or a rub. I am not sure which. My money is on stiff rubber bushings. The vibration of the drivetrain is getting passed right into the cabin due the the bushings being cold and stiff.
Mine does it in a straight line too, and I think you are right about the rubber bushings.
Try accelerating hard enough to make the noise, while exiting a right turn: I bet it will be worse. Then try the same thing in a left turn, I bet it will be a bit better.
Now you get what I am saying?