RS5 Exhaust Flap Issues Causing Engine Noise Problems

Had a similar problem with my 2013 RS4 last winter. With some experience working on exhaust components, I initially thought I could diagnose it myself, but the issue turned out to be more complex. The symptoms matched yours exactly, loud cold starts and the exhaust flaps were definitely stuck. The flap motor had completely failed, causing the valves to remain in one position. After checking the wiring which was intact, it became clear the actuator itself was the culprit. Took it to a workshop specializing in performance exhausts. They confirmed the exhaust flap actuator needed replacement. Total repair cost was 190 Euro including labor, and they completed the work in about 2 hours. To better assist with your case, could you share: Is the noise constant or does it vary with RPM? What specific fault code are you getting? Have you noticed any changes in engine performance? Are all exhaust valves affected or just one side? These details would help determine if your issue matches what I experienced with my RS4.

Just completed the 120000 KM service last month, so I can confirm recent inspection history. Thanks for your detailed feedback. The noise definitely varies with RPM, louder at higher revs. Getting fault code P2104 which points to the exhaust flap actuator control circuit. Engine performance feels slightly reduced, especially during acceleration. Checked the flap motor operation manually and its definitely not moving on the right side. Left side seems to work normally. Good to know your repair was straightforward, 190 Euro sounds reasonable considering the exhaust system complexity in these cars. The exhaust components on my RS5 have never been replaced, so its likely the original flap actuator finally gave up. Will get it checked by a specialist since the exhaust valves might need adjustment too.

Thanks for the additional details about your RS5. The symptoms you describe match exactly what I experienced before replacing my flap actuator. The P2104 code combined with the one-sided flap issue strongly suggests a failed actuator rather than a control circuit problem. When my RS4 had this problem, I noticed the exhaust noise was also uneven between sides, since one flap was stuck while the other worked normally. The exhaust flaps are definitely a common wear point around 120000 KM. The varying noise with RPM is typical when the flaps cant regulate flow properly. My performance also dipped noticeably until the repair was done. Since your left side is still operational, you might get away with just replacing the right flap actuator. However, given the mileage, it would be smart to have both checked. The labor cost wont increase much to do both sides while the system is apart. The exhaust components should be inspected for any additional wear while the actuators are being replaced. My repair included a quick valve adjustment which helped restore the proper exhaust noise levels. Let us know what the specialist finds. The repair should be similar in scope to what I had done on my RS4.

The workshop confirmed the diagnosis today, its definitely the right side flap actuator thats failed. Based on their inspection, the exhaust valves and other components look fine, so Im optimistic this will be a straightforward fix like yours. Got quoted 210 Euro for the repair including parts and labor. They can get it done tomorrow morning. Since the left actuator tested fine and the exhaust repair specialist didnt see any other issues, Im just going ahead with replacing the faulty right side unit. Really appreciate your detailed feedback about your similar experience. The exhaust noise and performance issues match exactly what you described. Looking forward to getting the proper exhaust sound back and normal engine performance. Will keep this thread updated once the repair is complete in case others run into similar flap actuator problems with these engines. Good to know these are common wear items around this mileage. Thanks again for helping confirm my diagnosis and sharing your repair costs for comparison.