Vibrating after stop the engine

[whokid]

I found that something was vibrating from the back every time I shut the engine after drive.
The sound is coming from the back, vibrate for like few seconds and stop, then keep countinuing just like a mobile with the vibrate on....
It is a common thing or something wrong with my S.
Any one help

[garett]

from the back? your stationery i presume.

only thing i could think of would be your fuel pump.

[zhong]

Apparently, if you release your fuel cap after a long drive it will stop.

It sounds like a truck from a distance yeh? freaky sh*t.

[AusS2000]

It's a little solenoid that keeps your fuel tank pressurised so fuel doesn't evaporate. It will happen repeatedly if your fuel cap isn't on properly.

[zhong]

^ "Isn't on properly" are you sure? It happens to me all the time.. And Im positive that it's on properly ("3 clicks according to s2ki").

[AusS2000]

If it isn't on properly it will happen all the time, but just because it happens all the time doesn't necessarily mean your cap isn't on properly. Just means your fuel tank isn't sealing as well as it should.

[whokid]

I am sure the fuel cap is on properly. Its not really loud, but its noticeable when I park the car in a closing area

[18dim]

mine does it too.
im sure its the fuel pump, (depressurising or bleeding)