"Pete" wrote

> This is actually quite common on many Audis. Most of the time, the
fuel
> sending unit needs replacing.

I also forgot to mention that in the US, somewhere around year 2000,
there was a whole Audi customer service action that included free
replacement of fuel sending units with the updated ones (apparently the
older ones on '96-'99 model years were prone to premature failures).
This was specifically for the A6. So, you may want to call Audi
Customer Relations in the UK and see if they had something similar going
and if so, they should fix it for free, even if you're no longer under
warranty.

Cheers,

Pete