03 Boxster S...what is this sound ???
 

Take a listen to this video and let me know if you've had this problem or what you think it may be. Thanks : )

https://youtu.be/c8v8lsIujVc

So here is what happened:

1. I heard this noise with no other symptoms, I thought, coming from the tank, no brainer, its the pump. Replaced the pump...easy. Did not solve the problem.
2. Still no other symptoms other than the noise Then I did some more research and found the comments about the Fuel Tank Vent Valve on Filler Neck, (aka Bleeder Valve), I changed that. Did not fix the noise, AND I was able to fill the tank once but last time I tried to fill the tank it wont accept the fuel.
3. So now Im looking for help. Any help is appreciated.

Thanks. : )

Inspect the fuel cap seal very closely - cracked?
Use an "Engine Ear" to pinpoint the exact source of the sound.

Thanks, cap is OK. Sound is coming from the hole near the gas cap, you can see in the video the sound stops when I put my finger over it.

This noise comes from a bad bleed valve (number 13 on the chart).

Part number from 98 on is 996 201 143 01

http://986forum.com/forums/uploads02...1460076503.jpg

Regards, Markus

Danke Markus, but I have already changed that part. Any other ideas?

Well looks like Im off to the independent shop. Damn, in 10 years of having the car other than the clutch this is the only thing I could not do myself. : (

Hello Pete,

sorry, hadn't seen your last post.

If you open the fuel tank cap while the engine is running, does the noise go away?

Regards, Markus

Thanks everyone for the comments.

I saw on another post there is a sensor that can easily fall out when changing the Fuel Tank Vent Valve, I took it all apart again and correctly installed the sensor that sits in between the fuel tank vent valve on the filler neck. With the sensor back in the right place all is well, the noise is gone and I can fill with gas again. : )

Another Festivus MIRACLE!

Glad it worked out.

Fantastic that you were able to determine the issue and fix it yourself.