Buzzing sound(like hairclipper), gas tank region, car park for 4 hrs
 

2 days ago, park the car at 4h30PM in the garage, (we were suppose to received 30cm(1 foot) of snow yesterday, I think we received more than that:mad0260:), anyways, did not hears anything weird at that moment, 4 hours later, so around 8h30PM, I go back in the garage, there is that buzzing sound,like a hairclipper or for more electronic inclined people like a relay that not able to close properly when energized, the sound is loud and its is comming from under around gas tank.

I decide to turn the key to power on position in the car(not starting it) to see if sound would stay there after, heard the normal sound(fuel pump, ...), buzzing sound disappeared, turn back off the car, no more sound!!

So for sure its not a shortcircuit in the wiring that would have energized some component when there no key in the car as the sound would have not disappeared.

What component go be buzzing like that 4 hrs after parking the car?

I think I remember hearing about an exhaust test that the car performs....some time after the car has been shut off,... correct me if I am wrong..

http://www.ft86club.com/forums/showthread.php?t=16534
and

http://www.ft86club.com/forums/showthread.php?t=17147

If the noise is like the one in the videos of the second link, it is the sound of the fuel system doing a fuel evaporation leakage check and is a normal function of the car.

evap/purge valve sounds
normal,

yes there are aliens under the hood

hehe

Yes, 100% normal.

Read your owner's manual kiddies.

Its the sound in the video link, thanks for the info, I have to admit I did not go through the manual. Never heard that in other car, is it common in other make/car?

Most new cars do this, my 2006 Toyota Tacoma listed in my signature does this as well. It has to do with new emissions standards. Basically 4 hours after you turn off your car, the car automatically checks for leaks in the fuel system. It's normal.