Hey, lately i've been experiencing a humming noise coming from underneith my car (it seems) when im idling and driving...sometimes it hums right wen i start it up, sometimes it waits til i put it in reverse. Idk what it could be? mabel fuel pump?

could anyone help me out?

 

The fuel pumps do hum a bit. My in-tank pump gets a little noisy when I'm low on fuel mainly because it's above the fuel level with anything below a 1/2 of a tank. Below the car you'll hear the external pump humming all of the time. It's just inside and infront of the left rear tire.