Fuel tank leak

There should be a rubber gasket ( big O-ring ) under the gas cap that squashes against the filler neck when tightened.  Either it isn't there, or it isn't think enough.  Take the existing gas cap to a NAPA or other auto parts store and tell them your problem.  They should be able to help with a gasket or new cap.

@Gordon Nichols @Carlos P i concur...the rubber gasket under this caps becomes FUBAR sometimes.....another thing is to loop the vent tube up & over itself in the fender well instead of straight down

Here are some pic of the cap. What do you think?

Looking at the cap doesn't tell us much - It's how it fits to the filler neck that's important.

Also, JNC's comment about the vent hose is important, too - It could be leaking fumes that you're smelling from the tank vent.  Find that and either install a 1-way valve (auto parts store, again) or put a loop in it in the wheel well to act as a valve.

another thing is to loop the vent tube up & over itself in the fender well instead of straight down => do you mind taking a picture of that or quick video? I am a total noob. And the car is brand new.

do you mean making this kind of loop?  Sorry, I am a newbie

And it is dangerous to drive with this or I should bring it to a shop asap?

@Carlos P   Don't sweat the questions - we were all noobies once.

I don't believe it's dangerous enough to panic over - Many others have had to overcome this, too.

The vent hose loop you show is working as a vent into the tank, but won't prevent the fumes from easily escaping while sitting.  It's better to move the loop farther along the hose and make the loop go down instead of up as you show it so that it will collect a bit of gas in the loop to act as a fume valve, just like the plumbing trap under a sink.  Usually, we do that loop out in the fender well, away from the front trunk a bit, just because there's more room to do a proper loop.  If you take it to someone to look at it, just print out this thread and show it to them - they'll prob'ly understand and can help.

You can also install one of these in the vent hose and forget about the loopy thing:

https://shop.advanceautoparts....wcB&gclsrc=aw.ds

I have one of these instead of a loop in the vent hose and it's been working fine for 20 years.  If you go to any auto parts store and give them the Dorman part number ( 47149 or NOE 7301347 at NAPA ) they can look it up and get you one or it's equivalent.

Just blow through it to see which direction it offers resistance (it's a one-way valve) and install it such that the airflow goes into the tank, not away from it.  You can install it at home, anywhere along the length of the vent hose.

Good luck!

Thank you so much! My stress level dropped back to normal! Thank you all!

Carlos

Wonder if you could spray some silicon on the gas cap rubber and slightly tap the 2 ears so it tightens more against the seal?  Summer id bad for gas vapor smell - a full tank of gas expands in the heat and forces itself out of the gas tank --- so don't fill so much in the summer.  Even old VW's used charcoal cannisters in the fuel system - no just a loop.

Gentlemen,

The external breather Standt gas caps everybody uses fail in many ways - enough so that I carry a spare, and have the PN associated with my account at O'Reillys.

The most obvious is the black neoprene seal, which oddly is not really fuel-safe. Every so often under spirited driving, it'll swell up and leak. It might go back into shape afterward, but I've never had any luck getting them to seal again.

The other way they fail is for the breather apparatus (which is blocked off in a cap with an external breather) to begin leaking by. Several years ago there was a thread regarding this problem, where somebody (@Sacto Mitch?) recommended just filling the thing with epoxy. I've never tried this, but I thought it was brilliant.

Fortunately, a new cap is less than $10. I'm in Denver visiting my daughter, son and law, and grandkids, or I'd wander out to the garage and provide a PN. I'm sure somebody else will have it. If not, I'll provide it when I get back to my desk.

Thank you so much for the help! The new fuel cap with a good gasket did the trick!
I am so blessed to be part of this community!

And another satisfied customer!  

I wonder what is being fixed in the Mechanicsburg, PA, Marriott Courtyards Hotel this weekend?

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@Stan Galat , here's a link to that old post, where I discovered my 'unvented' cap actually had plenty of vents in it. Here's the photo:

I just used some household glue to seal the gaps, but six years later, it's still good. That blue stuff I made a gasket out of is still OK, too, so I'm still using the same cap.

Most of the fuel smell, it turned out, wasn't coming from the leaking cap, but from the vent line splashing raw gas down the inside of the fender, under the car. A high loop in the line (also in the fender well) fixed that.

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This morning the garage didn’t smell anymore to fuel and while driving there is no more fuel smell or leak around the cap. wOOt! Thank you all for the help!

I put a loop in my vent hose, but would still smell gas on hard left corners due to sloshing, especially when the tank was full. I put one of these little check valves on the end of the hose. Problem solved!

I had a bad experience with a check valve.  I filled my tank very full with cold gas.  Then, as the gas warmed up it expanded.  Because of the check valve, the added volume of gas couldn't escape and the expansion deformed the top of my tank and caused it to bulge up.

Now I don't use a check valve just a loop in the vent line.

That is interesting!

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A loop is all you need, but it has to be done right.

The trick is getting the highest point of the loop several inches above the top of the filler. You can do that if you make the loop in the wheel well, at the top of the fender (near the base of the windshield).

Here's the one I put in my car and there have been no escaping fumes since. Ignore the fuel filter I included, which turned out to be completely unnecessary. The fat hose is the line VS installed to bring hot air to the defroster vent. It just served as a convenient mount for the gas tank vent loop.

The only thing that's important here is the height of the top of the loop. No matter how hard you corner, gas won't be driven up that high, so it just drains back into the tank, and liquid gas in the loop serves as a trap, keeping fumes from escaping.

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Brilliant! The law of physics :-)
thank you