Car Humming



I just bought a 2002 Honda Accord, manual transmission, and it has a humming noise that I’m worried about.

Whenever I get into higher gears, and therefore the revving of the engine is quieter, I can hear a humming noise. It’s constant and increases in pitch, but not volume, as the car goes faster. As far as I can tell, it’s coming from the rear of the car, but it’s a little hard to tell. One very noticeable thing is that the humming noise disappears when I’m going around a bend to the right, but not to the left. Also I can put the car in neutral and coast, and the noise is still there (decreasing in pitch as the car slows).

I kinda figure it’s a wheel bearing, but according to the “Car Talk Noise Emporium” it sounds more like a bad differential.

What does everyone thing it is, and what are the potential hazards if it is the differential and it fails? (I know the hazards of a wheel bearing failing)


There are lots of possibilities, but I would guess tyres.


I checked the tire pressure, and they’re all even. How could I be sure it’s the tire and not a bearing? I plan on doing the whole lifting one wheel off the ground and spinning it test this afternoon.
Should I be looking for any tread wear? Or could I replace the tires with the spare one at a time and see if the noise goes away?


It must be a wheel bearing because the differential in your vehicle is part of the transaxle. So it’s located at the front of the vehicle, not the back of the vehicle.



Ditto Tester and the bad bearing will probably be on the right rear wheel.


I’ll third that. If the humming is that loud and noticeable a mechanic should not have trouble verifying this.


Ok, new thought. What if the sound doesn’t disappear because I’m taking a bend to the right (and therefore placing less stress on a wheel bearing), but because I’m turning the wheel past a certain degree? If I change lanes quickly, then the sound goes away. And when taking a bend, there is a very definite point where the sound disappears/reappears.


What you describe are the symtoms of a worn wheel bearing.