RS6 Stalling Issues Linked to Fuel System Problems

I had a very similar issue with my 2018 RS7 last summer. Have some experience working on cars but mainly stick to basic maintenance. The symptoms match exactly what I experienced, stalling at idle and degraded performance. Initially thought it was fuel contamination from a bad fuel source, but after taking it to the workshop, they found it was actually a loose connection on the fuel pump wiring harness. The repair was straightforward once diagnosed, they had to clean the connector pins and properly reseat the plug connection. Total cost was 95 Euro including diagnostic time. Since the fix, no more stalling issues and performance returned to normal. Would definitely recommend getting it checked soon, as fuel system issues can potentially affect your combustion chamber if unaddressed. The faulty connection can cause irregular fuel delivery, leading to poor combustion and possible engine damage. To help diagnose further: Have you noticed any specific conditions when the stalling occurs more frequently? When was your last fuel filter change? Did you notice these issues immediately after refueling somewhere new? Any unusual sounds from the fuel pump area when turning the key? These details would help determine if your issue is similar to what I experienced with the wiring connection.

Current mileage is 183618 KM since new, last service completed at authorized workshop 2 months ago. After reading up on similar cases online, I think my issue could be related to clogged fuel injectors. Used a higher octane fuel with fuel additives last week, which seemed to improve the engine knock slightly. The fuel system symptoms match what others experienced with dirty injectors, especially the stalling at idle and poor fuel economy. Did anyone try running injector cleaner through their system before taking it to a workshop? Want to rule out simple fixes before investing in major repairs. The fuel mixture seems off based on how it runs, and I notice it getting worse in stop-and-go traffic.

The injector cleaner route is exactly what I tried before finding my wiring issue. While it helped temporarily with my RS7, it turned out to be masking the real problem with the fuel pump connection. From your symptoms and mileage, a clogged injector diagnosis makes sense. The fuel mixture issues you describe, especially getting worse in stop-and-go traffic, align with dirty injectors. Running quality fuel additives through the system is a good first diagnostic step. My recommendation based on experience: Run a full tank with premium injector cleaner, Monitor if stalling improves over 2-3 tanks, Check fuel filter condition during your next service, Have fuel pressure tested if symptoms persist The fuel additives helped initially with my car too, but the underlying fuel system problem needed proper diagnosis. If cleaning doesnt resolve it within a few tanks, professional testing of the entire fuel system would be wise to prevent potential long-term engine damage. Watch for any changes in how the engine runs after using the cleaner. While injector issues are common at this mileage, intermittent fuel pump or pressure regulator problems can show similar symptoms. The fuel contamination angle is worth investigating too, especially if issues started after using a new fuel source.

Thanks for all the advice. I'm going to try the injector cleaner approach first since its a relatively cheap solution. Just picked up a bottle of premium cleaner from the parts store for 25 Euro. The fuel economy has definitely taken a hit lately, and the engine knock is most noticeable when the engine is cold. Will run through a few tanks with the cleaner and monitor if the stalling improves. Already scheduled an appointment at the workshop next week to check the fuel system if this doesnt work. Interesting point about the fuel pump wiring, will have them check that too during diagnostics. Better to catch any potential issues early before they cause more serious engine damage. The fact that higher octane fuel seemed to help makes me hopeful its just dirty injectors, but want to be thorough with the diagnosis. Will report back after running through the cleaning process and getting a proper fuel system inspection. May need that fuel filter changed anyway given the mileage.