# fuel leak & smell when tank full



## ryanjn (Mar 3, 2009)

If ever I fill my 04 A6 2.7 tank to full and park overnight, in the morning the garage smells of gas, and there are 2-3 drips on the floor just behind the drivers side rear tire.
I had the dealer investigate, and apart from servicing a recalled fuel nipple of some sorts, they could only trace the leak to be at the top of the tank. Their diagnostic to proceed further was upwards of $400 since the exhaust had to be removed. The serviceman tried selling me on replacing the fuel tank all together, since it would save me on labor, though I couldn't wrap my head around what atop the fuel tank would fail that could not be replaced








...until I stumbled upon this thread http://www.audiworld.com/tech/eng81.shtml
I will fill the tank up to full, drive home to park, and access this gasket to check for leaks, though this particular issue does not indicate any dripping, just odor. 
Does anyone have any other suggestions as to what may be the cause of the leak? I have since only filled to half-tank, and no longer have any smells or leaks, though this isn't a long term solution.


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## ryanjn (Mar 3, 2009)

bump for any ideas?


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## Uncle Joseph (Nov 5, 2008)

*Re: (ryanjn)*

Are you topping off your tank? As in, continuing to fill it to a even dollar amount, after the auto-shutoff has stopped the fuel? Doing this can cause a seal to rupture in the top of the tank (the rollover valve, IIRC). If you continue to top off the tank with this ruptured seal, you will leak some fuel at every fill-up. The fuel will splash out a bit until the fuel level decreases somewhat. This repair involves removing the whole tank. Don't know if that is what's causing your particular problem, but this is a problem on many makes of cars...Audi even puts a warning on some gas caps not to top off the tank.


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## 16vsilverstreak (Dec 5, 2001)

*Re: (ryanjn)*

Is this A6 covered under the roll over valve recall?


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## ryanjn (Mar 3, 2009)

The car was serviced immediately following the recall notice. All that was replaced was some fuel nipple. The dealer said they must remove the entire tank to inspect where the leak may be (since they 'traced' it from being at the top of the tank.
I have since only filled the tank to 3/4ths, unless going on a longer road trip, and have had no leaking issues that I am aware of.


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## euronutz1089 (Nov 17, 2009)

*Re: fuel leak & smell when tank full (ryanjn)*

pull the rear seat I believe there is a acess pannel to the fuel sending unit the the o ring is not sealed right I have seen this many times after some one has installed the pump improperly


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## ryanjn (Mar 3, 2009)

*Re: fuel leak & smell when tank full (euronutz1089)*


_Quote, originally posted by *euronutz1089* »_pull the rear seat I believe there is a acess pannel to the fuel sending unit the the o ring is not sealed right I have seen this many times after some one has installed the pump improperly

I've pulled the seat out to reveal the panel, though there was no fuel smell in the car (never has been). It's certainly worth another look, which I'll do this weekend. I never did remove the access panel itself, just noticed no residue or odor from that area. Thanks!


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