My wife's 2006 A4 2.0 has trouble starting after every fill up. Crank it- wont start, crank again it sputters and dies. After the second or third try it will start, runs rough for a few seconds then is fine. Every start after that it fires right up. The check engine light is on and dealer said it shows a major fuel leak. There is no smell of gas. Dealer said they would have to investigate further to determine the cause. Anyone ever had this problem or have any ideas?

 

I'm going to assume you mean a fuel EVAP system leak? Chances are, your N80 (EVAP purge valve) is bad, but if that's not it, you usually have to do a smoke test of the EVAP system to find it. Do you have the error code? A simple scanner can at least get the number so you can go from there.

 

The check engine light has been on throwing a code according to Audi and my private mechanic for a fuel leak. The starting issue after fillup has been the last month or so. I am going to replace the evap valve N80 and see if that helps with the fillup issue. The car is to have an inspection this month so I will have my mechanic clear the codes then and see if they come back.

 

Well, if actual fuel is leaking, that's a safety issue and you should definitely address that. Hope the N80 fixes the hard starting issue for you. If you can get the actual code (a free AutoZone scan will give you that much), we may be able to help further.

 

I think Fuel Leak it for the EVAP system leak not an actual fuel leak. Kind of like when it says to tighten the gas cap. King is right on the starting issue. Change the N80 valve should resolve the issue. When you have Audi, mechanic, or Auto Zone pull codes be sure to write them down. Really helps out.

 

Thanks everyone- Just changed the solenoid- hardest part was getting the factory clamps off (dremel with cutting blade did the trick)-took it to the gas station, filled her up, crossed my fingers, and she fired right up. Next step is to go to Autozone to run and clear the codes and see if the check engine light remains off now.
Thanks again for everyone's help.

 

Just got back from autozone. The codes were P0442 evap control system small leak, P0455 evap control system large leak, and P0299 Turbocharger/Supercharger underboost. I decided to by a $50 OBD2 code reader and I reset the codes. Codes stayed off on the 10 mile ride home. Hopefully the N80 evap solenoid did the trick. I am concerned about the turbo code so probably the next thing that will have to be replaced is the turbo recirculation valve. This is my wife's car and I have only started driving it recently. I remember it being quite peppy, it feels fairly sluggish, so perhaps that turbo valve is the culprit. Any thoughts?

 

Try the diverter valve (DV) first. It's a cheap part and easy to do. If you have the original diaphragm DV, it's almost certainly the culprit.

 

CEL came back on this morning driving to work. Checked codes and the Evap codes are clear only the 0299 code for the turbo came back. I ordered the DV and plan on changing that this weekend. I removed the underbelly cover to get a look at where the DV is located and noticed that the factory snub mount was partially gone (literally) and the rest of it was crumbling like a stale muffin when touched. Needless to say i put in an order for a polyurethane one from ECS and will change that at the same time as the DV. Car only has 75k miles, but it is 11 years old now. Mother time is undefeated.

 

Good job. Both of those are pretty easy to do. You may notice a bit more idle vibration with the poly mount, but it doesn't bother me.

The top bolt for the DV is blind--just do it by feel. I believe they are either 5 or 5.5mm allen.