Audi S6 Fuel System Troubles Causing Stalls and Power Loss

As an S8 owner with similar symptoms last year (2011 model, 4.0 TFSI), this sounds exactly like my high pressure fuel pump failure. The automotive repair involved replacing the entire pump assembly. The rough idling and power loss are classic signs of fuel delivery issues in these engines. The car maintenance was quite extensive since the high pressure pump is integrated into the engine management system. My engine misfire symptoms matched yours, unstable idle, unusual stalls at stops, and significant power reduction. The check engine light was persistent, and diagnostic testing confirmed fuel injection system pressure problems. This is considered a serious repair that requires specialized tools and expertise. The fuel system work includes: Removing intake manifold, Replacing high pressure pump, Installing new fuel pressure sensors, Full system pressure testing, ECU adaptation procedures In these engines, when the high pressure pump starts failing, it typically gets worse quickly. Continuing to drive risks additional engine damage. Would strongly recommend having it checked by an Audi specialist who can properly diagnose the fuel delivery system. The repair time typically takes 2-3 days due to the complexity of accessing and testing all components.

Thanks for the detailed insight on the fuel pump failure. Dealing with these exact issues on my S6 right now and your description matches my symptoms perfectly. Really helpful to know about the full scope of automotive repair needed, definitely explains the rough idle and fuel delivery problems I'm experiencing. Before I take it to a specialist for the high pressure pump replacement, curious what the final cost was for your repair? Also wondering if youve had any other fuel injection issues pop up since getting it fixed? The car maintenance expenses on these engines can get steep, so trying to budget properly for this repair. Thanks again for sharing your experience.

My high pressure pump repair was completed last month and has completely resolved the fuel delivery problems. The total cost came to 1510 Euro for parts and labor, which included replacing the defective fuel volume regulator that was causing the rough idling issues. Since fixing these components, the engine runs smoothly with no check engine lights or performance issues. The fuel injection system is working perfectly now, and fuel economy has actually improved slightly. The car sensors are all reporting normal readings, and the stalling problem is completely gone. No additional fuel system problems have emerged since the repair. The specialist did a thorough job testing all related components and recalibrating the engine management system. If your symptoms match what I experienced, getting it fixed sooner rather than later is worth the investment to prevent potential cascade failures in the fuel delivery system. Looking back, investing in proper repairs by a qualified technician was the right call for maintaining the cars long-term reliability and performance.

I finally got the car back from the specialist mechanic yesterday. The repair took 3 days as predicted, and the final diagnosis confirmed what everyone suggested, a failing high pressure fuel pump. Engine misfire issues were definitely related to the degraded pump performance. The total repair came to 1650 Euro, which included: New high pressure pump, Fuel pressure sensors, System diagnostic testing, Labor costs The car maintenance was worth every cent though. The rough idling has completely disappeared, and the engine runs perfectly smooth now. No more check engine lights or stalling at stops. Fuel efficiency has actually improved quite a bit compared to before. Really glad I got this fixed at a proper specialist rather than the first mechanic who couldnt properly diagnose the issue. The thorough testing they did on the whole fuel system gives me confidence that everything is working correctly now. For anyone facing similar symptoms, definitely dont wait too long to get it checked out. The quick repair prevented any additional damage to the fuel injection system.