I was driving my wife's passat at the weekend and a couple of times while stationary I noticed a strange mild juddering sensation which only lasted a couple of seconds. The car has also randomly been making an electrical whirring noise from the rear both whilst stationary and on the move. The noise is different to that made by the electric park brake. On one occasion the car juddered whilst making the electrical sound. The electrical sound lasts for five to ten seconds. I am wondering if it is fuel pump related. Has anyone got any ideas?

The car is an my 12.5 and has only covered 5500 Kms.

Thanks