PetC

For all those in snow-country, am wondering if any of you are experiencing problems filling your A5/S5s with fuel. Let me first say that when un-screwing the cap there is substantial air pressure holding the cap in and one has to get a good grip and pull kind of hard on the cap to release it. Setting the filler nozzle on 'fast', the nozzle clicks-off quite soon. From then on filling is painfully slow as the nozzle continues to click-off unless the fuel is going in at a rate of around 10 cents a second.

I should mention that we have enough snow here that it is packing around the wheel wells pretty heavily. I was thinking that the fuel tank venting likely exits in the wheel well and the ice now there is preventing that, but I don't know. The Audi dealer here tells me that the fuel tank fumes vent into the tank, but that makes NO sense to me. Air vents FROM the tank, not TO the tank, or so I thought. Maybe it vents back to the engine??? Anyone here have the same experience or thoughts about the tank venting, etc.?

MonzaA5

Never experienced this problem, though we haven't had much snow in Toronto this winter (it's +10 and raining right now...)

The "clicking off" is often a result of holding the nozzle at the wrong angle (i.e. pushing it in too much).

PetC

Well, be assured that the nozzle has been tried at almost all angles except upside down and at all insertion depths, without any improvement other than the less the nozzle is inserted, the fuel flow is slightly faster, indicating to me that the tank's air is venting out of the filler pipe.

IAS5

is this happening at all pumps, or one particular station? i have no problems anywhere, with the exception of one gas station--don't know why...

PetC

This has happened three consecutive times at three different service stations, with three different fill-attendants, including myself.

fred44nl

this alone means that there is a venting problem.
excessive pressure from the fuel tank goes into a carbon filter.
from there it goes into the free air.
the fumes certainly don't go into the tank, as this would increase the pressure in the tank, when the outside temps. are rising high in summer (can't wait )

but it seems you have 2 venting problems.
not only can't you get rid of over-pressure, but pulling hard on the filler-cap, to open it, says you have an under-presure problem as well.

the dealer is giving you the run-around !!!!

can't you park the car in a heated garage, so you can loose all the snow and ice that has been built up ??

BlueSander

The air filter connected to the fuel tank is behind the rear driver side wheel liner. If you park your car after a long drive and hear thumping noise from the rear then your filter is mostlikely to be clogged. Replacement part is sold at dealer for around $50. This is a very simple DIY project.

s4master1

the fumes not suppose to vent to the air, they get pushed to the charcoal canister where they liquify and then send to the engine when is running,
the filter is to filter the air the pump uses to pressurize the tank during testing, is possible in the past you overfilled the tank and saturated the canister, since is so cold the liquid has not yet vaporize enought to clear the charcoal and send to the engine, try not filling up the tank all the way for a while so it has room to evaporate the liquid to the engine and dry

PetC

Problem solved. After the car broke down (fuel starved) on the highway and had to be towed into Audi, they discovered that the roll-over valve had failed. Apparently this valve stops fuel from venting and spilling fuel out of the fill pipe and also shuts down the fuel pump when the car flips. Its progressive failing prevented fuel from properly filling the tank - my initial problem. When it fails, it really fails. Because air was prevented from venting, and the fuel pump continued to pump, the fuel tank partially collapsed. They are replacing the tank, pump, carbon canister and roll-over valve. I presume they do a wheel alignment since the entire rear wheel assembly comes out to replace this equipment (fuel tank, at least).
Thanks to all contributors here.