I have a 90 dodge spirit es. As I go down the road my car sounds like a jet airplane taking off. As I go faster the louder that the noise becomes. As I slow down the noise slows down as well. It sounds like its comming from the wheels but not sure which ones. Any ideas what it is? Is it possible that it is the wheel bearings, if so how hard is it to replace them.

 

Could be wheel bearings, could be tires, could be anything that is rotating in relation to the wheels.
Make some wide sweeping turns (on/off ramps) and listen for changes as you turn in one direction or the other.
If the noise gets louder when turning left, it's something on the right side.
If the noise gets louder when turning right, it's something on the left side.
If you can't tell a difference it may be on both sides or in the transaxle.

Could be the Gerbil in your trunk.

 

Jack the car up enough so the wheels are off the ground. Lock the steering wheel and grab the tire and try to move the wheel left to right and up and down. If it moves, and you can feel play in the hub, then its the bearings. If not have the tires balanced and check your brakes.

 

those are all great ways of diag also ck the surface of your tire w/your hands to ck for worn shocks,a feathersd feeling on the tires or
hearing a bouncing motion!