2000 Porsche Boxster fuel filler vent bleeder valve

try spraying water on belt if it stops replace belt an dtensioner

whistle is coming from gas filler are not engine

check to see if the evap canister purge valve is staying open and causing a vacuum leak through tank which would be the whistle you are hearing. also check to make sure your gas cap is in good condition. is your check engine light on? if it is then have it scanned for codes

If you are referring to the valve at the top of filler pipe then it was just replaced as was gas cap and no engine check light. Had car analyzed but no faults present. How would I test new vent bleeder valve or as you may be calling purge valve?

unplug it and see if whistle stops is easiest way. it may set a code though. just to make sure we are talking about the same item, it is in the pic with arrow pointing to it, this will go to a vacuum source. it cold also be a tank pressure sensor problem or a shutoff valve problem which I would think that a smoke test be performed on this system would or could find your problem. also check your secondary air injection system that can be making the noise as well. item 3 is the anti run on valve and it may leak there or in one of the hoses. see pics

replaced #7 on first diagram and whistle is coming from that vicinity right front by gas fill

try replacing number 1 then

Where is purge valve located on vehicle #1part. Is this too difficult for me to do on own.

i'm pretty sure this is it, if this doesn't solve your problem then have a pro look at it because it can be something else. been a while for me for these cars.

Mechanic feels it is vent line part # 996-201-255-08 do you concur?

he's probably right, it is probably blocked which they can do on cars that aren't run all the time so the system doesn't work right. Only way would be to try to get air through it to see if it's blocked or not.

I imagine the only way to test is take off and then blow air through?

or disconnect at both ends if possible and do the same thing.

Well $1277 dollars later it turns out purge valve was culprit as you suggested and I relayed to mechanic. He replaced all five valves in evap up front. If you come across this problem insist that the $79 purge valve be replaced first. It could save you a grand. Even though valve was bad there was no fault code.

thanks for the reply lot of guys don't want to do the checking just throw parts at it. but we dont' run across many porches either. Its' unfortunate yo had to put somuch cash into it to get it fixed for the cheaper part however. Happy driving though.