Audi RS5 Fuel System Issues: Common Fixes Revealed

Having some experience with automotive diagnosis, I faced similar symptoms with my 2010 S5, which shares many components with your RS5. The gasoline delivery issues you describe match what I encountered. After multiple engine stalling incidents, I took it to a workshop where they discovered it wasnt actually the fuel pump causing the problems. The real culprit was a loose connection in the wiring harness leading to the fuel pump. The symptoms were identical to pump failure, but the fix was much simpler. The repair involved cleaning and properly securing the connections, plus replacing a damaged plug. Total cost was 95 Euro and the car has run perfectly since. The whole process took about 2 hours at the workshop. Before suggesting more specific solutions, could you share: Current mileage on your RS5, When was the last fuel system service, Any unusual sounds when starting the car, Whether the issues started suddenly or developed gradually This information would help determine if youre dealing with a similar electrical issue or if theres another problem in the fuel delivery system.

My RS5 has 80888 KM and last had a full service 3 months ago. The car performance issues started gradually over the past month. When starting, theres a distinct whining noise from the rear of the car, which I didnt mention initially. I think this additional info about the sound might help pinpoint if its really the fuel pump. Based on your experience, could the wiring harness issue still be the cause even with the noise? Looking for a clear direction before moving forward with car repairs.

Thanks for providing those additional details about your RS5. The whining noise you describe from the rear actually changes my initial thoughts about it being similar to my wiring harness issue. In my car mechanics experience, that specific noise combined with your symptoms strongly points toward fuel pump problems after all. When my S5 had the wiring issue, it never made any unusual sounds. A failing fuel pump typically produces that characteristic whining noise during startup, which is a key difference in automotive diagnosis. The gradual onset of issues over a month, combined with the whining sound, suggests your fuel pump is losing pressure. This matches the classic symptoms we discussed: Engine stalling, Rough running, Increased fuel consumption, Starting difficulties The fact these issues have developed after 80888 KM is quite typical for fuel pump wear. In my case, after fixing the initial wiring problem, I actually ended up replacing the fuel pump at around 95000 KM as preventive maintenance. Given these updated symptoms, I recommend having the fuel pressure tested before proceeding with any repairs. This will definitively confirm if gasoline delivery is compromised due to pump failure.

Thanks for that detailed response about the fuel pump noise. That makes a lot of sense about the whining sound being a key indicator. Given my RS5s symptoms match the classic fuel pump failure signs you mentioned, I think Ill proceed with getting the fuel pressure tested first. Better to confirm the exact issue before spending money on parts. The gradual performance decline combined with that rear whining noise does seem to point toward pump issues rather than wiring. Since the car is at 80888 KM, maybe its just reached the natural end of the fuel pumps life. Ill get it checked and report back on what the auto repair shop finds during testing. Really helpful to know your repair timeline matched similar mileage. That gives me more confidence its likely the fuel pump needing replacement rather than an electrical problem in the fuel system.