Hey,

i have 02.5 A4 1.8T Quattro and a few days ago it started making a humming sound from between the rear wheels.
As soon asIstart the caryou can hearthe humming sound. I far as I can tell the sound does not change whenI rev the engine or make a turn.

thanks for your help!

 

Generally this has known to be the fuel pump. When I changed my Fuel Pressure regulator from the standard 4bar to a 5bar to support my K04 it started humming. I was told because of the higher FTP this was common and not to worry.

If you have not changed anything dealing with your fuel system your pump may be dying, this is not uncommon either.

Is the 02.5 a B5? I thought the B6 start with 03 but for all I know it could be a mid tear change. If it is a B5 like mine the fuel pump is accessible from inside your trunk under the bed lining. A round hatch will need to be removed and then you have access to the fuel pump.

Thanks,
Neal

 

it's a b6, So i need change the fuel filter

 

Hmm...I thought the b6 started in 02, my car is an 02 and its the b6. I've also heard that the fuel pumps have a tendancy to go out.

 

Hehe 02 it is then, I couldnt remember the change over year =)

Fuel filter as you said could also be the problem and its not a bad idea in preventitive maintenance to change it. Its cheap too just a pain in the butt to do, at least on my B5 it was. Might want to check AUDIDIY.com to see if they have a guide on doing it for the B6.

If the fuel filter doesnt do the trick I would look into the fuel pump.

 

^+1 I found the filter to be pretty easy to change on my b6, took me all of ten minutes. All you have to do is jack up the rear passenger side, take the plate covering the filter off, take out the bracket holding the filter, then just take off the old filter and everything else is reverse of removal

 

Thanks for your help