Gas smell with full tank

[efnfast]

Lately after filling up I get a strong fuel smell from the back of the car, both driver/passenger side, at idle and when driving (i.e., I can smell it inside the car).

When I get home and park the car, next day the garage reeks of fuel at the rear of the car (front smells fine). After ~30 miles or so of driving post-fillup then the smell goes away completely.

Nothing appears to be leaking and it only smells of fuel at a full tank.

I did have both rear fenders removed/replaced a few months ago ... is there something the bodyshop might have forgot to connect (although I would think it would smell of gas all the time if this were the case)

 

[03' White Snake]

Could be the charcoal canister is not hooked up right. It is in the drivers side rear bumper/fender area behind the tire. 1 or 2 plastic lines from the tank hook up to it.

 

[MG0h3]

Sure you’re not getting some leakage at the neck to tank connection?

First step is getting under there after fueling up. They probably didn’t get something right with the neck.


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[TitanSvt]

Check the hat. I had a similar leak awhile back. Mine would smell after refuel because my hat was leaking and would only leak when the tank was full. Where the hat sits is recessed, so if it's small, good chance it's not leaking onto the ground or just leaking into the tank cover/guard and spilling out while driving

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[efnfast]

Could be the charcoal canister is not hooked up right. It is in the drivers side rear bumper/fender area behind the tire. 1 or 2 plastic lines from the tank hook up to it.

Couldn't hurt to check when it warms up (although I would think a charcoal canister issue would be all the time, not just as full tank)

Sure you’re not getting some leakage at the neck to tank connection?

First step is getting under there after fueling up. They probably didn’t get something right with the neck.


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I don't see any dips/leaks on the ground anywhere after filling up (although my mind does go to filler neck given it has to be moved when doing the fenders)

Check the hat. I had a similar leak awhile back. Mine would smell after refuel because my hat was leaking and would only leak when the tank was full. Where the hat sits is recessed, so if it's small, good chance it's not leaking onto the ground or just leaking into the tank cover/guard and spilling out while driving

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interesting theory ... I hadn't considered that possibility although it would make a lot of sense (no going to see any fuel drips when filling up and it would evaporate on the plastic cover and leave the cover reaking).

What would be the easiest way to test - stuff a bunch of rags around the fuel hat and sender, fill up and see if damp?

 

[TitanSvt]

Filler up, drop the tank just enough to get your hand up there. Feel around for the hat, if your hand gets wet, probably the hat seal

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[efnfast]

mystery solved - filler neck gasket - it was only -10* outside today so I poked my head around ... upper corner of gasket was wet and wiping it with a rag made the rag reek of fuel. also signs of something pooling on the tank and running in to the cover, which is probably why I never saw anything leaking.

I imagine it probably tore when they took out the fender and had the fuel filler flopping around ... guess 20yr old gaskets don't like to be disturbed, who knew (sic)

 

[efnfast]

My filler neck is also pretty corroded - I imagine once I start yanking on it it's going to snap. *le sigh*

My gas tank is pretty rusty on the exterior so I was thinking about just replacing it. I've found all the parts online, except for the big blue vent valve. Apparently that part is no longer made and there's a 99% chance I will break my existing one when I try to remove it.

So far the only solution I've found online has been to cut it out of the gas tank.

I can't seriously believe there is no aftermarket solution for a piece of the gas tank that goes to millions of cars????

 

[FleeMan]

https://lmr.com/item/LRS-9593B/2000-04-Mustang-Fuel-Tank-Vapor-Valve

 

[efnfast]

https://lmr.com/item/LRS-9593B/2000-04-Mustang-Fuel-Tank-Vapor-Valve

the gas tank has 2 valves - a little blue valve (that guy) and a big blue valve with 2 ports .... the second one is the one I'm looking for .... that apparently doesn't exist unless you cut it out of a tank.........

 

[efnfast]

Youtube does not make you prepared for how difficult this is if you've driven 275k of wonderful salt filled winter miles.

Both nipples on the original fill neck broke off when trying to remove the hoses from them ... and then I got to spend a good hour digging the seized-in broken nipples out of the hoses without damaging the hoses

The fill neck itself broke when trying to remove it from the tank ... but i had enough left to remove it

I figured I should change the fuel filter .... one of the quick disconnects was seized up really good and it took me like an hour to get it to pop off ..... pretty black fluid after 275k miles, guess I shouldn't be surprised

One of the new OEM Ford fill neck's holes on the mounting flange was stripped out

And to top it off, when I was leaning in the trunk to tighten up the trunk floor/fill neck gasket my hand punched through the trunk floor .... guess who's getting a patch panel tomorrow

Fuuuuun.

 

[FleeMan]

God bless, lol.