I had the same sound coming from the fuel filler. Are you having any difficulty filling fuel or have you filled the tank and give it a "top off" by one more squeeze of gas and had it gush some out? I replaced this part that allowed fuel to flow, but if I do the top off it will gush out so I learned a lesson - don't do it.
https://www.pelicanparts.com/More_Info/99620114301.htm?pn=996-201-143-01-M100&SVSVSI=0912&DID=15028