ok my car had some light mods when i bought it and i think it has a pump. when i put my ear up like where my rear seat meets the floor i can here a light buzzing noise, and sometimes i can here the same buzzing noise but like 100X louder and i can even here it from outside of the car. it kinda sounds like the motor the pushes out your windshield washer fluid does this sound like a walbro?

thanks..

-nick

 

Yes you have a Whinebro pump . It gets louder with more load in hot days.