A few days ago I have posted a thread about the high pitch noise at the rear end.
Now I track down the whistle coming from the fuel pump.
Usually the noise starts whenever I start the engine. So this time I started the engine, the noise just stopped as soon as I pulled out the fuel pump fuse (fuse 33). The Car is 04 T5

Now I am considering the causes to this high pitch whine.
1. whether a clogged fuel filter can cause a noisy fuel pump?
2. whether a fuel pressure regulator problem can cause fuel pump whining?
3. bad fuel pump?
May some one give me some suggestion?
Thanks a lot in advance!