RS7 Camshaft Sync Issue Triggers Power Loss & Warnings

Had similar issues with my 2018 RS5. The symptoms were identical, flashing check engine light and severe performance drop. Diagnostic revealed a faulty crankshaft position sensor that was causing engine synchronization problems between the crankshaft and camshaft. The crankshaft sensor had deteriorated, sending incorrect timing signals to the ECU. This caused the engine to misfire and run rich, explaining the poor fuel economy. The engine control unit was getting confused about the precise position of the crankshaft relative to the camshaft timing. It was a serious issue that required immediate attention since continuous driving could have led to engine damage. The repair involved replacing the crankshaft position sensor and clearing the engine codes. The cam sensor was also tested but was functioning correctly. After the fix, engine performance returned to normal and the misfire issues disappeared completely. These timing-related problems need proper diagnosis with professional scanning tools to pinpoint the exact cause.

Thanks for sharing your experience. My car had very similar symptoms and I am wondering about the repair costs. Did you remember how much you paid for the crankshaft position sensor replacement? The timing chain assembly looked fine in my case but the reference values were way off, causing constant misfires. Just got it fixed last week but want to compare costs since these repairs can vary a lot. Also curious if you had any other issues pop up since the repair was done? My mechanic mentioned these problems sometimes come back if the wiring harness is damaged.

Good news, your symptoms match exactly what I experienced. I paid 340 Euro for the complete crankshaft sensor replacement which fixed the reference value issues. This seems fair compared to what others have reported for similar repairs. The timing chain was also intact in my case, the problem was isolated to the faulty sensor causing incorrect crankshaft to camshaft reference values. Once replaced, the engine light cleared and the misfires stopped completely. Its been over 8 months since my repair and no issues have returned. Your mechanics concern about the wiring harness is valid, but in my experience, when the sensor itself is replaced properly, these problems rarely come back. The new sensor restored proper synchronization between the crankshaft and cam sensor readings. Make sure they performed a thorough diagnostic scan after the repair to confirm all reference values are now within spec. This helps ensure the engine timing is properly synchronized and operating efficiently.

I wanted to share a quick update about my repair experience. Took it to a certified shop last week and the diagnosis confirmed the cam sensor issues. The total repair came to 380 Euro, which included replacing the crankshaft position sensor and a full diagnostic scan. The timing belt and related components checked out fine, it was purely a sensor problem causing the engine synchronization issues. The mechanic showed me the faulty sensor which had significant wear on the magnetic pickup. After the repair, the engine light cleared immediately and the car runs perfectly again. Fuel economy is back to normal and the performance issues are completely resolved. The shop did a thorough check of the wiring harness and found no damage, so hopefully this fixes the problem for good. Thanks again for sharing your experience, it helped confirm my suspicions and gave me confidence in the repair decision. The cost was very much in line with what you paid, which is reassuring.