RSQ3 Timing Issues Causing Power and Performance Loss

As someone with some experience working on Audi engines, I had a very similar issue with my 2020 RS3. The symptoms you describe match exactly what I experienced, poor performance, engine light, and irregular engine behavior. In my case, the crankshaft sensor was failing, causing incorrect reference values between the crankshaft and camshaft positions. This affected engine synchronization and timing, leading to the reduced power mode you mentioned. The repair involved: Diagnostic testing to confirm sensor failure, Replacing the crank sensor, Clearing fault codes, Testing engine timing synchronization Total cost was 340 Euro including parts and labor. The job took about 2 hours. Before suggesting anything specific for your case, could you share: Current mileage, Any recent maintenance history, Whether the timing belt has been checked recently, If the issue occurs more during cold starts or when engine is warm These symptoms could potentially be related to timing belt issues or other sensor failures, but the crankshaft sensor is a common culprit in these models when showing these specific symptoms.

Thanks for your detailed response. My RSQ3 has 82706 KM and had its last service 3 months ago. The misfire symptoms started appearing suddenly last week. The engine light came on during highway driving, not during cold starts. The timing belt has not been inspected since the last service. Based on your experience with the crank sensor replacement, this sounds like it could be a similar issue. Will have the workshop check these components specifically. The repair cost you mentioned seems reasonable for this type of work.

Thanks for providing those additional details. The timing of your symptoms, appearing suddenly during highway driving rather than cold starts, matches exactly what happened with my RS3. When the crank sensor starts failing, it often deteriorates quickly, leading to sudden misfire issues and engine synchronization problems. The fact that it happened at highway speeds rather than cold starts strongly suggests a sensor issue rather than a timing belt problem. Since your last service was recent, and with that mileage, a timing belt failure would be quite unusual. In my case, the workshop first verified the crank sensor signals using diagnostic equipment before replacement. This helped confirm it wasnt a more complex timing issue. One thing to note, after my repair, the fuel consumption returned to normal within about 2 tank fills as the engine control unit readjusted its timing parameters. You might experience something similar once fixed. Make sure the workshop checks both the crank sensor wiring harness and the sensor itself, as sometimes the wiring can be the culprit. In my repair, they found some minor insulation wear on the wiring that they fixed while replacing the sensor.

Thanks for all the insights. This has been really helpful in understanding what I'm dealing with. Based on the similar symptoms and circumstances you described, I feel more confident its likely a crankshaft sensor issue rather than a more serious timing belt problem. The fact that my engine light came on during highway driving, just like in your case, makes me think were dealing with the same root cause. Ill make sure to have the workshop check both the sensor and wiring harness when I take it in tomorrow. Good to know about the fuel consumption taking a couple of tank fills to normalize after the repair, that will help set the right expectations. The 340 Euro repair cost seems fair for the work involved. Really appreciate you sharing your experience with such detail. Ill update the forum once I get it fixed in case others run into similar issues with their engine light and performance problems.