Noisy Fuel Pump ... Again !

[bad930]

Ok, this is a repost from the Rennlist Forum

Well I had a new Fuel Pump installed in my car, and I still have a loud whining noise from somewhere in the front of the car..

So as I continued to poke around the car, I noticed when i released the fuel filler cap the whining noise would disappear.. when I would tighten the cap back on the noise would gradually build up again ..

The noise is like a cat meowing intermittently..and occasionally it wines for longer .. but like i said when i release the fuel cap the noise goes..

I'm totally stumped .. anyone have any ideas ??

Its driving me crazy :cursing:

[Loren]

Model and year of your car please...

[bad930]

Model and year of your car please...

Hi Loren, 98 Carrera 2, 3.4 Tiptronic

thx

[Loren]

Is this a US car? because the US/Canada cars are different than the RoW cars.

[bad930]

Is this a US car? because the US/Canada cars are different than the RoW cars.

ROW car Loren. Thx :)

[Loren]

On some of the early 996's there were problems with hose ties near the fuel filler. This could cause a variety of problems from fuel filling problems to a buzzing noise at the filler.

On US/Canada cars there is a fuel return that also returns vapors to the fuel tank - on some of those cars there is a valve that can fail that will cause a similar buzzing sound.

Those are the areas I would look at first...

[bad930]

On some of the early 996's there were problems with hose ties near the fuel filler. This could cause a variety of problems from fuel filling problems to a buzzing noise at the filler.

On US/Canada cars there is a fuel return that also returns vapors to the fuel tank - on some of those cars there is a valve that can fail that will cause a similar buzzing sound.

Those are the areas I would look at first...

Ok I removed the guard liner and theres a black box in there with lines connected to the fuel tank, I'm assuming these are return vapour lines?

This seems to be where the noise is coming from , there's a valve coming out of one of the lines. should I replace this valve?

I'll take photos if this will make it easier

Really appreciate your help on this Loren. Thx

[Loren]

Here is the pic (poor quality) of the issue in the TSB.

This is inside the tank - the fuel pump is at the bottom of the pic.