allestraße

Got the car back from New Country Audi at 9:30 am yesterday morning - a rather less frenetic experience than Friday with the Fire dept et al. They lived up to their promise and did work on the car Friday night. Service advisor who had been working with me on this wasn't working Saturday, so I didn't get the full scoop, but one of his colleagues told me that the problem was the gasket around the fuel gauge sender. I'm not sure of the precise location of this unit, but I would think that one would need a pretty full tank of fuel for a faulty seal in this area to be leaking gas. One explanation is that on the day the event occurred, it was cold outside and I did something unusual for me, bought gas on the way to work. As I work less than a mile from the gas station and the gasoline may have expanded in the relative warmth of the parking garage, this could have forced it through the faulty gasket.

I'm off to Europe for a week today. I'll try to find out more when I return.

srs

The sender unit seals onto the top of the passenger side saddle gas tank like a ball jar lid. It is supposed to click into place. I my case, after body repairs the shop cross-threaded it when putting the fuel system back together, and so it didn't seal correctly. It was the same with me - it wasn't noticable until the tank was completely filled.

Access to this sender unit is via a trap door under the back seat. It's a pretty easy (although messy) fix to replace the gasket and screw the thing back together.

What I still don't understand is why the "check engine" light doesn't come on. This is a pressurized fuel system. If you don't screw on the gas filler cap tightly the warning light comes on, why not in this case?

The other question that comes to mind is - did you have any recent work on the car that involved that fuel sender unit? How long has it been cross threaded?

In my case, I drove 220 miles with it that way before I found the problem. Luckily, it was pouring rain, so any leaking gas was diluted quickly with water. Also, while the gas leaks down the inboard side of that saddle tank, there is a heat shield between the tank and the hot exhaust (only about 3 inches away)!!