Audi S6 Fuel Pump Failure Causes Multiple Issues

Had the exact same symptoms on my 2008 Audi S4. The engine stalling and rough running turned out to be a failing fuel pump combined with corroded electrical connections at the pump assembly. Initial diagnosis showed fuel pressure dropping below spec, causing engine performance issues and increased consumption. The fuel system was struggling to maintain proper pressure, leading to the stalling especially at idle. The repair involved replacing the complete fuel pump assembly and rewiring the electrical connections. It was a serious repair that required dropping the fuel tank. The check engine light was triggered by low fuel pressure codes similar to your situation. After the pump replacement, all symptoms cleared up, no more stalling, normal fuel consumption returned, and engine performance was fully restored. The car ran perfectly for another 45000km with no fuel system issues. Would strongly recommend getting this checked soon, as continued pump failure can damage other fuel system components and leave you stranded. Best to have a certified shop do a proper fuel pressure test to confirm before replacing parts.

Thanks for sharing your S4 experience. This does sound very similar to my fuel pump problems. I am also getting the same fuel pressure error codes and stalling issues. Quick question, do you remember roughly how much you paid for the full repair with labor? Also wondering if anything else failed since then or if the fix took care of all the engine performance problems completely? I am getting quotes now and want to make sure they are in a reasonable range before committing to the work. The fuel injector system seems fine based on the diagnostic, but I want to address this before the pump failure causes more damage.

Just had the repair done last week actually. Turns out it was exactly what I suspected, a faulty connection at the fuel pump assembly causing intermittent fuel delivery issues. The mechanic found the plug connection was corroded and causing the pump to malfunction. Much simpler fix than I initially thought. Only cost 95 Euro for the electrical repair work since they didnt need to replace the entire fuel pump. The car performance is back to normal now with no stalling or rough running. Fuel consumption has returned to standard levels too. This was definitely cheaper than the complete pump replacement I had expected. A proper diagnosis by a certified mechanic saved quite a bit of money by identifying the actual issue rather than just swapping parts. All engine performance problems cleared up after fixing the connection. The fuel pump is working perfectly now and maintaining proper pressure. No other issues have cropped up since the repair. Would suggest getting your fuel system checked soon, ongoing pump failure can lead to more expensive repairs if left unaddressed.

Thanks again everyone. Just wanted to update on how this turned out. Finally took the car to a different mechanic for a proper automotive diagnosis. They ran pressure tests and found the same fuel delivery problems mentioned here. Ended up needing the full fuel pump assembly replaced, which cost 780 Euro including labor. More than the electrical fix some got away with, but still better than I expected for dropping the fuel tank. They also cleaned the fuel injectors while they were at it. Car runs perfectly now, no more engine stalling or rough idle. Fuel consumption is back to normal and the check engine light finally cleared. The mechanic showed me the old pump which was pretty worn out. Glad I switched shops and got it fixed before it completely failed. Been driving for about 2 weeks since the repair with zero issues. The engine performance is completely restored. Definitely recommend anyone with similar symptoms get their fuel system checked promptly rather than waiting for a complete pump failure.