Grrrr....Woo-Woo Noise From Fuel Filler Door is Back.

[Need_for_speed]

Originally Posted by mipstien

I am going to follow this as well. I fixed my noise by replacing the valve under the intake. But I still occasionally hear it at 3000ish rpm. I think that it may just be the hole+speed of air = perfect setup to howl.

I hope that someone figures it out eventually. As like most of you I am tired of throwing money at it.

I just ordered the valve for the fuel filler neck. It's the least expensive of the remaining options, and in my opinion, probably the most likely remaining culprit. I should have it in place by the end of the month. I'll keep you posted.

[Boxstard]

Originally Posted by Need_for_speed

I just ordered the valve for the fuel filler neck. It's the least expensive of the remaining options, and in my opinion, probably the most likely remaining culprit. I should have it in place by the end of the month. I'll keep you posted.

I am also having this type of noise issue, but only at idle on warmer days above 75F or so with half tank of less fuel, under isolated situation and never noticed it while driving. I changed the filler neck valve which reduced the noise level and duration but still there...

Hope this thread lead to a solution.

[Run]

I have had this issue for 3 YEARS. Recently (last year) my fuel sending unit started leaking. I have not yet replaced it as the car is sitting in storage. I am wondering if there was an issue with it all these years causing that noise. Mine would always do it at steady rpm let off the gas or brake and the sound was gone. I hope to get around to getting it fixed in the next month or so will be interesting if that damn sound goes away.

[Gelbster]

Originally Posted by Run

I have had this issue for 3 YEARS. Recently (last year) my fuel sending unit started leaking. .... Mine would always do it at steady rpm let off the gas or brake and the sound was gone. I hope to get around to getting it fixed in the next month or so will be interesting if that damn sound goes away.

Sounds like this is vacuum related ? Steady rpm = low vacuum, idle/over-run =suddenly much higher vacuum

[Run]

I will take a look into the vacuum thing. This is my third car 2nd Porsche and honestly I think its time to go to a new home 2k miles in almost 3 years

[Need_for_speed]

So today I replaced the valve on the fuel fill tube, using the Pelican instructions as a guide. It was a tricky little job, but after a lot of fiddling around, I was able to get the new valve in place.

Note: not shown in the Pelican instructions, there's this very slender little electrical component, looks like a transducer, that fits into a corner of the fuel filler valve. The wire attached to it is taped to the fill tube. I noticed it by accident after I removed the old valve. What the heck is this part?

Anyway, we did a test drive and the woo-hoo is still there. It's extremely intermittent, totally independent of throttle position. It almost seems like it has something to do with the way air flows over the car. Now I'm starting to wonder if it's a hood adjustment thing, or if I have a weatherstripping issue somewhere. I've replaced just about every damn component on the evap system, so now I'm grasping at straws...

[Need_for_speed]

So, just to clarify, when I removed the vent valve, this little electrical part fell out and was dangling by a thin wire taped to the filler neck. There wasn't anything in the Pelican guide to tell me what it was, but I assumed that it must fit inside the vent valve. I didn't get a picture of it, but it's around an inch and a half long and about an eighth of an inch thick. It looked to me like a transducer or some sort of switch. It appeared to fit perfectly in the inside corner of the vent valve, so I placed it there when I replaced the switch.

After a little research, it turns out that the part in question is a reed switch and it does indeed fit inside the vent valve. A number of people have replaced the valve without realizing this switch fell out, then discover they can't put gas in the tank. I must have placed mine in the correct spot as I just filled up with no issue. Whew! Luckily, I happened to see this little part dangling from the wire. If it had fallen down behind the fill pipe, I probably wouldn't have noticed.

[Racer Boy]

Originally Posted by Need_for_speed

Anyway, we did a test drive and the woo-hoo is still there. It's extremely intermittent, totally independent of throttle position. It almost seems like it has something to do with the way air flows over the car. Now I'm starting to wonder if it's a hood adjustment thing, or if I have a weatherstripping issue somewhere. I've replaced just about every damn component on the evap system, so now I'm grasping at straws...

You can try taping all the seams of the bodywork on the front of the car with duct tape. See if the noise goes away, and if it does, remove one piece of tape at a time until the noise comes back. Viola! You've found the culprit (hopefully).

The nice thing is that it is cheap to try that, tape is cheap. If it doesn't work, then you aren't out too much.