A noise like an airplane engine is caused by a front wheel bearing but you can never be sure which side is noisy by driving it. The best way I've found is to run the car on a hoist in gear and listen next to each one with a stethoscope.
The good news is if you don't have anti-lock brakes, both bearings will be the same so if you replace the wrong one you can put the old one on the other side. Be sure there is never any vehicle weight on a wheel bearing when the large axle nut is loose. Doing so will instantly make a good bearing noisy. The torque value on those nuts is critical too. The new bearing will come with a sheet stating the torque spec. Most call for 180 foot pounds but some GM cars call for up to 240 foot pounds.
Friday, May 17th, 2013 AT 10:10 PM