Boiling Fuel

[Oishi]

Hey guys, did a search for this and came up with nada. Drove for about 2+ hrs. today and stopped for gas. Gauge at less than 1/4 tank. Lowest I have ever run it, wanted a full tank of fresh for an upcoming trip. Anyway, with the fuel cap off, I could hear bubbling/ boiling sound deep in the fuel tank. I went ahead and filled, but only got 14 gals. in, when I estimated it would take at least 18. No other issues (no fire or explosion). All heat shields under car present and intact.
Any thoughts?
Edit; 2003 Spyder Gt US spec 60k Miles.

 

[allandwf]

Possibly blocked carbon filter?

 

[Oishi]

blocked carbon filter?

Yep, that's one thing I thought of. Hot day, low level of liquid in tank, remove cap and pressure drops, vapor pressure causes remaining fuel to begin to boil. Any other thoughts?

 

[Zep]

Could well be the purge valve, they have been known to have issues, although they normally fail open.

 

[allandwf]

I don't think it's boiling, just equalising pressure. A blocked, or partially blocked, filter can make it difficult to fill hence some people put the nozzle in side ways etc. you are really just slowing the fill process. My 3200 was a bit like that.

 

[CatmanV2]

I really doubt it was boiling. I doubt the pump can lower the pressure that much. Sure @Zep can do the maths

C

 

[Oneball]

Fuel in the disaerator draining back into the tank?

It’s the silver box on top of the tank that sits between the vent pipes and the carbon canister/emissions system. I assume it’s meant to condense as much vapour as possible out of the breathers.

If there’s no problems why worry.