S6 Diesel Stalling: Faulty Camshaft Sensor Alert

Had the exact same symptoms on a 2018 S4 TDI. The engine control unit was logging intermittent camshaft position sensor faults. After sensor testing confirmed the issue, found the encoder wheel on the camshaft was damaged, causing incorrect ignition timing and unusual stalling. The symptoms match perfectly, rough idle, stalling, and hard starts are classic signs of camshaft position sensor problems. In my case, the damaged encoder wheel was causing the sensor to read incorrect positions, leading to engine control issues. This was quite serious and required removing the valve cover to replace both the encoder wheel and sensor. The engine needs precise camshaft position data for proper fuel injection timing. When this fails, the engine management system gets confused, leading to the stalling and starting problems. Would strongly suggest getting it diagnosed properly with proper diagnostic equipment. These symptoms wont resolve themselves and will likely get worse over time. The check engine light indicates the computer has stored specific fault codes that will point to the exact issue.

Thanks for sharing your experience. Your encoder wheel issue sounds exactly like what I am dealing with in my S6. The engine misfire symptoms and stalling match up perfectly. Going to take it in next week for proper sensor testing to confirm. Question, do you remember roughly what the total repair cost was for the encoder wheel and camshaft sensor replacement? Also, has everything been running smoothly since the fix or did you encounter any other related issues?

Got my S4 back from the shop 3 months ago after fixing the faulty camshaft sensor and encoder wheel issue. Total repair came to 695 Euro, which included parts and labor for replacing both components. The mechanic confirmed the camshaft sensor was defective and the encoder wheel had damage causing incorrect position readings. Since the repair, the engine has been running perfectly, no more stalling, rough idles, or hard starts. The check engine light cleared up and hasnt returned. The proper ignition timing has been restored, and fuel efficiency actually improved slightly as well. Make sure they thoroughly test both components. In my case, the damaged encoder wheel was causing the sensor to report incorrect camshaft positions, leading to the engine control issues. A proper diagnosis with the right equipment will quickly pinpoint if you have the same underlying problem. Just addressing the sensor alone might not solve it if the encoder wheel is also damaged like mine was. The complete fix really resolved all the symptoms for me.

Thanks for the input. Finally got my S6 diagnosed and fixed last week. The issue turned out exactly as suspected, both a faulty camshaft sensor and damaged encoder wheel were causing the problems. Total repair cost came to 780 Euro, bit more than expected but worth every cent. The mechanic showed me the old encoder wheel which had visible wear marks causing incorrect readings. They replaced both parts and did a full sensor testing sequence to verify everything was working correctly. The difference is night and day. No more engine misfire issues, stalling, or hard starts. The check engine light cleared immediately after the repair and the engine control system is working perfectly now. Really glad I got it sorted before any serious damage occurred. Going to be more selective about mechanic work going forward though. Previous shop probably missed these warning signs during routine maintenance. At least now I know what to watch out for if similar symptoms ever come up again.