Its the gas tank, all A6's share the same gas tank design for quattro models. There are about 4-5 evap nipples on the top of the tank that have little metal sleeves inside them, the sleeve slowly works its way out and makes the nipple easy to bend or break off. Its not enough usually to cause a check engine light but you WILL see gas on the floor. I had to replace gas tanks on 2.8,3.0, and 2.7T models for this same problem.

 

AUditech79's right. It's common for the gas tank to be replaced on that car.

 

Are the nipples on top of the tank? that's where I would expect an evaporative emmisions nipple. If so, that would mean that the only gas that would leak out would be gas that is splashing around during driving, correct? So, there would be no puddle in the garage, correct? But he would still smell the gas as it evaporates, correct? Then, he would be faced with an outrageous repair bill, correct?

Or, would a little silicon seal solve the problem?

Bob

 

Thank you all for helping me, as of now 3/4 gas in the tank no smell, no ppuddle on the floor. I keep you posted after my next fill up.This is my firstAudi .Maybe my mechanic was right whenn he said stay with the Saab. I have a 92 with 275000 miles a 98 with 195000 miles and a 05 with 62000 miles.

 

gasoline smell is back along with the -check engine - light

 

The code reader reads: Po456 avaporative emission system leak detected ( very small leak)

 

After the Audi dealer changed the gas tank in july 08( under recall) the smell is gone. The engine light was still on with code PO 456 till the purge valve was changed nov 08. Since than I lost power on I 95 highway 400 miles from my home with flashing engine light. In Augusta maine O'Conoor's WV dealer chenged 3 ignition coils and the problem was gone. Audi refunded the cost of repair. After that engine light again now the catalytic converter was gone -replaced by Audi under warranty. The timing belt was changed in feb 2010 along with water pump etc.