Loud Noise from area around gas cap

[HammerESQ]

I've got an interesting issue with my 2000 Boxster S.....

There is a loud 'whine' noise coming from the gas cap area. I have traced it down to a line that connects to the Carbon Canister Vent Valve housing.

I placed my finger over the line, and it's pulling a vacuum, but the noise in unbearable. I'm assuming it's the Carbon Canister Vent Valve, but I'm not sure, and would like others opinions before I start spending money.

Has anyone seen an issue like this before?

Thanks!

[CenterIsl]

Lots of folks have had this - I think if you searched for "whistle" rather than "whine" you'd find it.

I forget the details, but I believe this vent is just there for when you are filling your gas tank and should otherwise not be under pressure / vacuum. I've seen reference to a switch activated when the nozzle is inserted into the filler tube.

In my case I just put a piece of gaffer's tape (like duct tape but without residue) over the hole and unpeel it when filling the tank. Has worked fine for almost a year so far...