start sound

What do u mean by humming sound, (a)is it remains start after you switch off the engine?
(b)is it just vibrates after you switch it off?
In both the cases you need to get checked yours car switch. and the ECU(electronic Controle Unit) that manages the feul supply and air supply of the engine.

Hi Punwine
Thanks for your time. I think I should go to an auto electrician for this problem. Actually i have bought this used V40 recently and u know used cars have some minor problems most of the time.

Hi locaste,the noise you hear is normal all it is the electric fuel pump getting up to pressure,once it reach`s the pressure it will stop. The reason it has to do this is after the car has stood overnight or any length of time the fuel will return to the tank or evaporate so the fuel injection system needs the correct pressure to work properly hence the humming noise, hope this helps lee/mandy