Audi S6 Boost Issues: Whistling and Power Loss Alert

As someone with some experience working on Audis, I encountered a very similar issue with my 2015 Audi S4. The symptoms you describe match what I experienced, especially the whistling sound and erratic airflow sensor readings. The temperature sensor and charge sensor problems often stem from faulty wiring connections rather than the sensors themselves. In my case, the workshop found corroded plug connections affecting both the temperature gauge and airflow sensor readings. The fix was straightforward, they cleaned and reseated the connections, replaced some damaged wiring, and properly secured the air intake components. Total cost was 95 Euro for the repair including labor. Before suggesting specific solutions, could you provide: Current mileage, Any recent maintenance work, Whether the issue occurs more during cold or hot weather, If the check engine light is constant or intermittent, Any additional error codes from the diagnostic This information would help determine if your issue matches what I experienced or if there might be other factors involved with your S6. Also, worth checking if there are any technical service bulletins for your specific model year, as this was a known issue for certain production runs.

Thanks for the reply. My mileage is currently at 103158 KM and the last service was done 2 months ago. The airflow sensor issue emerged right after a period of heavy rain. The check engine light remains constant, no flickering. The automotive sensor problems seem to get worse during cold starts. The temperature gauge readings become especially erratic during the first 10 minutes of driving. I checked for visible damage around the air intake system but everything looks intact. I will take your advice about checking the wiring connections. Given the symptoms match your experience, I will have the charge sensor connections inspected first. Good to know the repair costs were reasonable in your case. The diagnostic showed only the single error code related to the charge sensor. No additional codes appeared during repeated scans.

Thanks for the additional details. Given the timing after heavy rain and cold start issues, this further confirms my initial suspicion about connection problems. My S4 showed nearly identical behavior with erratic temperature sensor readings during cold starts. A crucial detail I forgot to mention from my experience: water intrusion through the air intake caused corrosion at the charge sensor connector pins. The temperature fluctuation readings were a direct result of this moisture damage. The service tech found small water droplets inside the connector housing. Since your symptoms started after heavy rain, I strongly suggest having the charge sensor connector housing checked for moisture. The constant check engine light and single error code match my situation exactly. A quick tip: while the connectors are being inspected, have them check the air intake seals too. My repair actually revealed a slightly loose clamp that contributed to the whistling noise and inconsistent sensor readings. The repair should be similarly straightforward and cost-effective as mine was, especially since there are no additional error codes. The fact that the temperature sensor issues are most pronounced during cold starts is a classic sign of connection problems rather than a failed sensor unit.

Thanks for sharing those details. Hearing about your similar situation with the corrosion and moisture issues helps narrow down my problem. The air intake seal check is particularly relevant since my whistling noise matches what you described. The timing after the rain and the cold start temperature fluctuation issues certainly point toward moisture-related connection problems. Looking at the charge sensor area more closely, I notice what might be dampness around the connector housing. I will schedule a repair visit focusing on inspecting the connections and air intake seals. The single error code and consistent symptoms make me confident this can be resolved without major component replacements. Knowing your repair cost was around 95 Euro helps set reasonable expectations. Will update once I get this checked out, since others might benefit from knowing the final diagnosis and fix. The engine sensor issues seem more straightforward now that I understand the likely cause.