I also think its your lift pump in the fuel tank
It will cost you about £30 from GSF.
You dont need to depressurise the system to change the lift pump or fuel filter. The fuel filter is under the car near the driverside rear wheel and next to the main fuel pump. Its easy to change but the clamps may be a stuck or corroded.
To do the lift pump:
1) Disconnect your battery earth terminal.
2) Go in the boot and lift up / remove the carpet.
3) Undo the 3 screws holding down a large circular metal plate and remove it.
4) remove the electrical connector and fuel lines. You may need new jubilee clips for these.
5) using a block of wood and hammer tap the black plastic cap until it can be removed by hand.
6) carefully remove the lift pump and fuel gauge assembly from the fuel tank.
7) remove the lift pump from the assembly and replace. You may need to order a different strainer - VW dealers only I think. There are two different pump types with different intake diameters.
Refitting is straight forward and your low petrol whine - caused by air passing through the main pump - will be gone - with luck
