So I did something silly today. Gas cap attachment line is broken. Took cap off and left it on the fuel pump at the gas station.

Left it...

Drive home is on back roads and short but spirited.

Cars in garage - which is under family room - for an hour before the complaints about the smell start.

Go back down and the line between the vent flap and top of the filler neck is -full- of gas. It wasn't when I'd finished filling the tank.

Question: Is that normal?

Oh and after racing back to the garage I got the cap back. Which was an unexpected bonus. Smells (obviously) gone now.

 

I would be concerned that gas can travel between family room and garage. there should be no leaks between the house and garage
sorry can't help with the vent flap thingy.
curious did your cel go on?

 

It went through the open door to the basement, up the stairs and through the whole house. We were all in the family room.

CEL - Don't think so.
I'll look tomorrow night - only went to fill up because I'm taking a trip. It's only a couple of miles to the garage.

The bit I'm concerned here about is the backwash past the flap.

 

The backwash shouldn't be a problem. The gas should either slowly drain back into the tank or into the charcoal canister. If to the CC it will be pulled back through the intake and burned as long as your purge valve and related hardware is working correctly.

 

The gasoline being where it was was due to the missing cap, to state the obvious. Not normal but of course driving the car with the cap off is not normal.

Once in a great while when fueling one of my cars I'll get the fuel level a bit too high and when I remove the nozzle some fuel runs out and collects on top of the fuel tank flap. I just gently put the nozzle back into the tank fill tube and open the flap and the fuel drains into the fill tube.

With water you want to make sure the drain from the fill basin to the ground is working properly. This is to carry any gasoline spilled out of the basin and to the ground.

You can buy a new cap with a new tether. The tether on my Boxster gas cap broke and I bought a new cap/tether assembly -- I can't recall the cost but it was not much -- and removed the old tether connection then installed the new cap with its new tether.