Fuel smell inside the cabin

[A80Avant]

Weird issue that has developed over the past few months.

Car smells of fuel inside the cabin when left overnight as well as when driving at small speeds with the windows open.

Weirdly enough when the car is in the closed garage it doesn't smell outside, but mainly inside the cabin.

So far changed or checked:

N80 valve in operation with vems
New carbon canister
Fuel lines and fume lines
Adjusted tank cap and seal from the trunk
There is no pressure escaping from the tank when opening the cap to fill the tank

I cannot see any leaks from anywhere from the engine bay and under the car.

I will be checking the valve under the canister in case there is an issue with that although visually nothing was broken.

Anything else I should check?

[Klobsters]

Did you check for micro-cracks in the white fuel tank lid? They are sometimes very hard to notice but seems to be a very common fault.

[A80Avant]

Garage checked this today. I shall have a chat to them is that available as a part?
They did use more seal on the metal cap and still smells quite a bit

[Klobsters]

I don't think the metal cap matters in this case. I'm pretty sure that mine is barely sealed at all. The problems arise from either the white tank lid or the rubber seal around it (or a bad locking ring on top of that).
The part number for the white lid is 8A0201319A. The rubber seal is 1J0919133. Can't find the number for the locking ring.

[fourringsrus]

Slightly different car but my 225 quattro Audi TT,was doing this and I found a shredded breather hose which is now replaced and I have no more fuel smell in the car

[A80Avant]

Thanks! I'll order those

[Klobsters]

Found the locking ring number - 321201375A

[Henkjan]

Slightly different car but my 225 quattro Audi TT,was doing this and I found a shredded breather hose which is now replaced and I have no more fuel smell in the car

you mean the one going from the top of the tank to the filling pipe? had that happen on a typ85 once with the same symptoms: smell inside

[A80Avant]

Which one do you mean?

[anthonys2]

I had the same problem with mine last year and mine had a hair line crack in the fuel sender unit which sorted it out when I got mine replaced and to my knowledge this part is unavailable so got a good second hand one. If I left mine from one week to another you get in the cabin and the first thing I had to do was open the windows as it stank of fuel. Hope you get it sorted

[A80Avant]

Fuel sender you mean the white cap mentioned above?
According to the garage that seems to be intact and dry on inspection.

Did yours have any stains of fuel or clues?

[anthonys2]

yeah as mentioned above. I could hardly tell you really had to look very closely to see as it was so small the hair line crack and the other clue I got was the form under the carpet was starting to expand that sits above the fuel tank. when I changed mine I had the carpet out for a long time to get rid of the smell

[A80Avant]

I see... well I ordered the above parts and hope that will solve it

[A80Avant]

Weird thing is that the only other time it distinctly smells is when you first start the car or/ and you reach a traffic light, again occasionally, as if it's coming from the engine bay this time.

Now the grommets from my engine bay are a bit gone, after all the work done, most had to be cut wide open, and I assume smells from the engine could find themselves in the cabin easier. However that smell tends to be more noticeable with the windows open.

I don't know if this is related or just a red herring...

[Klobsters]

Both of these things can be explained with the same white lid. When you're moving, the fumes are mostly located in the back of the car but when you brake or stay stationary, they move to the front. Opened windows increase the air circulation around the driver so that can also bring the fumes to your nose.
Of course, there could be a different reason as well, but this is definitely a place to start. Also, if there was any fuel leaks in the engine bay, you would notice immediately just by opening the bonnet.