Gas filler neck / cap / tank / pressure issue.... SO ODD!

[Bijan]

Hey dudes.

I was driving up a trail Saturday. I had all windows down including rear window. My passengers and I started to smell gasoline. It got to the point of slight concern, so I started investigating. I looked in my side view mirror, and saw vapor fumes coming from the gas tank fill door.

I stopped the truck, turned it off, and popped the gas tank lid. I opened the cap, and it PSSSHSHHSHHSHSHHED really loud and long.

It then kept puking vapor out. Here is a video: it sounded like the gas was boiling in the tank, and the bubbles were coming up through the fill neck.
https://youtu.be/K1dqJ1E157w

You can see the drips below the cap door line - it def looks like some spilled out. I started with a full tank, and was at 3/4 tank when I noticed the issue.

I finished the trail - and nothing really happened that I can tell.

Any advice?

 

[Bijan]

b.u.m.p...

 

[Riceye]

A couple questions:

-Do you top off the tank after the fill nozzle clicks off?
-How much altitude did you gain when this happened?
-Was there a big swing in temps between filling up and when this happened?
-Have you tried pulling any obd codes?

I would guess your fuel tank evap system has a problem. When operational, any excess pressure should be relieved. Either the vent line is pinched/plugged somewhere, or the purge/canister is malfunctioning.

 

[Unner]

I assume there was a major elevation change when you noticed the noise? I had the same thing happen to me in Colorado before when I climbed a lot of elevation quickly on a trail. Mine wasn't bubbling, but that psshhh noise was there.

I had a rental Mustang a couple weekends ago that I took from sea level to 8,000 feet above sea level pretty quickly. It spilled some gas out of the tank as well, and that was a new car. Pressure changes at elevation can be weird. I doubt you did any damage, I'd keep driving it as is unless there is still an issue.