I drive a manual '96 Plymouth Neon that has about 161K. I'll relate my question to a washing machine. When your washing machine starts the spin cycle, you'll know if it's not balanced by the horrible knocking sound it emits. With my car, the faster I go, the louder she gets. It's just like the washing machine sound, except it's a lot faster and is more of a consistent humming nature. I noted that whenever I drive on a partial incline (when the right side of the lane is a bit higher than the left), she runs QUIET like she's supposed to. But the second it's flat ground, she's back to being loud. My first thought is to have her realigned. Any other thoughts? THANK YOU! : OD
Have the wheel bearings checked. SOON! The hum is the bearings pitted, the noise change is because of the pressure change on the bearing. Make sure the ground straps are still attached to the strut when you have the bearing changed.
Obvously have it verified first, but it sounds like the animal.