S8 Exhaust Flap Malfunction Hits Engine Performance

Had a similar issue with my 2020 RS7. The exhaust flap motor started malfunctioning during cold starts, creating irregular exhaust noise patterns. The exhaust valves were not operating correctly, causing the system to stay fully open. The repair required replacing the entire flap motor assembly and recalibrating the exhaust system controls. It was a serious issue because leaving it unfixed could lead to further damage to the exhaust components and potentially affect engine performance. The diagnostics revealed carbon buildup around the exhaust valves, which contributed to the sticking mechanism. The repair included cleaning the valve assembly and checking all connecting actuators. A complete system diagnosis was necessary to ensure no other exhaust components were affected. After the repair, the cold start sound returned to normal, and the exhaust flaps began operating as intended. Based on your description, the symptoms match almost exactly what I experienced. Would strongly recommend having it checked by an authorized dealer since these exhaust system issues can worsen if left unaddressed. Worth noting that this is a known wear item on performance models, often requiring attention around the 90000-100000km mark.

Thanks for sharing your experience with the RS7 exhaust flap issue. My S8 is showing very similar symptoms, especially during cold starts. Since getting it fixed, have you noticed any recurring problems with the exhaust flaps or flap actuator? Also, would you mind sharing the repair costs? Trying to budget for this fix and wondering if I should prepare for any additional exhaust blockage issues down the line.

Great to follow up about my RS7 experience. Since having the exhaust flap motor replaced and the system recalibrated, everything has worked flawlessly. The repair cost me 190 Euro total, which covered both parts and labor. The flap motor replacement fixed the cold start issues completely, and I have not experienced any exhaust blockage or performance problems since. The authorized shop thoroughly cleaned the exhaust system while doing the work, which likely helped prevent future problems. The engine performance returned to normal immediately after the fix, and the exhaust flaps now operate exactly as they should. Even after putting another 20000km on the car, the repair has held up perfectly. Based on my experience, once properly fixed, these exhaust system issues rarely come back. Just make sure whoever does the work checks for carbon buildup and cleans the surrounding components while they have everything apart.

Thanks everyone for the helpful feedback. I finally took my S8 to a certified shop last week. The mechanic confirmed it was indeed the exhaust flap motor causing the issues. The repair was straightforward and cost 220 Euro, slightly more than expected but worth every cent. The cold start noise is now back to normal and the engine performance has notably improved. They also cleaned out some carbon buildup they found while doing the work. The whole repair took about 3 hours. The exhaust system is working perfectly now, no more strange sounds or error codes. Really glad I got this fixed before it led to more serious exhaust components problems. Will definitely keep an eye on the mileage for future maintenance of these parts.