RSQ3 Exhaust Issues: Loud Cold Start and Flap Troubles

I had a similar issue with my 2017 RS3 and have some experience working with exhaust components. The symptoms you describe match exactly what I encountered, particularly that cold start noise and overall louder exhaust note. After experiencing these issues, I took my car to a workshop where they diagnosed a defective exhaust flap actuator. The whole repair, including parts and labor, cost me 190 Euro. The issue was affecting engine performance and could have led to more serious exhaust blockage if left unaddressed. The mechanic explained that these exhaust flaps are electronically controlled and can fail due to various reasons, from electrical issues to mechanical wear. In my case, the actuator had seized, preventing proper exhaust valve operation. Before suggesting more specific solutions, could you share: How many kilometers/miles are on your RSQ3? Are you getting any specific error codes? Does the noise change with different driving modes? Have you noticed any changes in fuel consumption? This information would help determine if your issue is identical to what I experienced and could guide you toward the most efficient repair path.

Last service was performed at 80738 KM. The error codes I am getting are P2261 and P0642. The noise does vary significantly between comfort and dynamic modes. I have noticed about a 15% increase in fuel consumption over the past month. Looking back at my records, I can confirm the exhaust valves were last inspected during my 75000 KM service interval, with no issues noted at that time. The engine performance started declining gradually about 3 weeks ago, coinciding with when I first noticed the unusual exhaust sounds. Your experience with the flap motor repair is particularly relevant, as the symptoms match what I am experiencing. The 190 Euro repair cost seems reasonable if it resolves these issues. The exhaust blockage possibility you mentioned is concerning. I will schedule a diagnostic check focusing specifically on the exhaust system components you highlighted.

Those error codes you mentioned definitely align with what I experienced in my RS3. P2261 typically relates to the turbocharger control, and P0642 often indicates voltage reference issues, both of which can affect exhaust valve operation and overall engine performance. During my repair, the mechanic discovered that the exhaust flap issues were actually causing additional strain on the turbocharger system, leading to similar error codes. The increased fuel consumption you noted (15%) matches almost exactly what I experienced before getting the repair done. Since your last valve inspection was at 75000 KM, and problems started showing at around 80000 KM, this timing is very similar to when my exhaust flaps began failing. The varying noise between driving modes is another clear indicator, my car exhibited the same behavior before the repair. The repair cost I mentioned (190 Euro) covered just the actuator replacement. Given your error codes, you might want to have them check the entire exhaust system, including the turbocharger connections, to prevent any recurring issues. The gradual decline in engine performance you mentioned suggests this could be more than just a simple actuator problem. Would recommend getting this checked soon, my delayed response to these symptoms led to more extensive exhaust repair needs.

Thanks for sharing those additional error codes and service details. The varying noise between driving modes really seems to confirm what you described about the exhaust flap actuator issue. Given my 80000+ KM reading and the similar timing of problems, I am definitely going to follow your repair recommendation. The matching symptoms, especially that 15% fuel consumption increase and error codes, make me confident this is the same exhaust system problem you encountered. I will book the car in this week and specifically request they inspect both the exhaust flaps and the turbocharger connections you mentioned. Better to address these exhaust valve issues now rather than risk more serious exhaust blockage problems developing. The 190 Euro repair cost provides a good benchmark for the actuator replacement. I will make sure to budget a bit more in case they find additional exhaust system components needing attention during the inspection. Really appreciate you sharing your experience, it has helped narrow down the likely cause and given me a clear action plan for getting this resolved.