Raw fuel smell from rear of vehicle 2007 Lincoln town car

[corcovado]

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MAKE: Lincoln
MODEL: Town Car
YEAR: 2007
MILES: 80,000
ENGINE: 4.6
DESCRIBE ISSUE...

.Hi all,
My 07 signature limited with 80,000 miles has a raw gas smell coming from the rear. No visible leaks, no over consumption of fuel. Coming from the rear wheel well areas.

However not all the time....and with various tank amounts (1/2, 3/4, etc)

So much so that on a hot day, with high humidity you can smell it inside the passenger cabin.

No check engine light on.

Definitely not under the hood, as I checked and double checked that.

Looked at filler neck, and where it goes into the tank, no evidence of leaking, no evidence of rust.

Any thoughts appreciated
Thanks

 

[billr]

Have it checked for codes, even it the CEL isn't on (it does work?).

 

[nickb2]

Probably a saturated evap canister, or a continuously venting canister. Highly recommend as Billr, said to read codes from the ECM/PCM.

You may want to get the evap system smoke tested. I may help narrow down diagnostic time to locate the fuel vapor leak that is causing this smell.

Normally, if no noticeable leaks are not found, you are just smelling fuel vapors and it is normal to get stronger smells on hot days as the pressure inside the tank will increase with outdoor temps. Simple principle of physics really. Most gasses expand with heat. Bingo.

Often times, a smoke test will reveal a stuck open canister vent valve. Yours is located here. See #1 of following diagram.

 

[nickb2]

Of note you will notice the breather tube is located exactly at rear wheel well passenger side.

I have seen numerous times a scanner able to actuate the vent solenoid but it is stuck in its bore and continuously vents the canister, hence not redirecting the vapors back to the engine for the core principle of what a evap system is for. Which is to burn the fuel vapors and not let them be released into the environment.

 

[corcovado]

Have it checked for codes, even it the CEL isn't on (it does work?).

Yes, CEL does work.
I will check for codes nonetheless.

 

[nickb2]

If your willing, try this out.

Incense smells better than gas.

 

[corcovado]

Probably a saturated evap canister, or a continuously venting canister. Highly recommend as Billr, said to read codes from the ECM/PCM.

You may want to get the evap system smoke tested. I may help narrow down diagnostic time to locate the fuel vapor leak that is causing this smell.

Normally, if no noticeable leaks are not found, you are just smelling fuel vapors and it is normal to get stronger smells on hot days as the pressure inside the tank will increase with outdoor temps. Simple principle of physics really. Most gasses expand with heat. Bingo.

Often times, a smoke test will reveal a stuck open canister vent valve. Yours is located here. See #1 of following diagram.

View attachment 9630

Ok, thanks I will check out the Evap system to see for any abnormalities.

 

[jd]

Different Ford product, but I had gas smell that traced to a broken down hose on the evap canister. Mine was a small "wiper hose" looking thing but with a 90* bend. I couldn't find one so I used a longer hose formed into a loop to get the ends connected.