Audi S4 Stalling: Bad Camshaft Sensor Warning Signs

Had the same issue with an Audi A4 2017 diesel. The check engine light came on, and the engine would stall at idle, particularly after cold starts. Initial sensor testing pointed to the camshaft position sensor, but the actual problem was more complex. The encoder wheel on the camshaft was worn, causing incorrect signals to the engine control module. This made the engine management system receive faulty timing data, leading to rough running and stalling. The crankshaft sensor readings were also affected due to the timing being off. The repair required removing the valve cover to access and replace the faulty encoder wheel and camshaft sensor assembly. This is a serious repair that needs precise timing adjustment afterward. The job typically takes several hours due to the complexity of accessing the components and ensuring proper calibration. If experiencing these symptoms, getting it checked promptly is crucial as continued running could affect other engine components. A specialized Audi workshop with proper diagnostic equipment should perform proper sensor testing to confirm the exact cause, as similar symptoms can also stem from other timing-related issues.

Thanks for sharing your experience. This matches my symptoms exactly, especially the cold start stalling and engine misfire issues. I checked with my local shop and they confirmed the camshaft sensor failure diagnosis. Planning to get it fixed this week. Did you remember the total repair cost for the encoder wheel and sensor replacement? Also curious if youve had any similar sensor-related problems since the fix? Want to make sure this is a long-term solution before spending the money.

Following my visit to the mechanic, I can confirm the repair completely resolved the engine misfire and stalling issues. The total cost came to 695 Euro, which covered both the encoder wheel replacement and the new camshaft position sensor. The job was completed 8 months ago, and the car has been running perfectly since then with no check engine light or cold start problems. The investment was worth it, as the proper repair prevented potential damage to other engine components that could have occurred if left unfixed. The symptoms you describe match exactly what I experienced, and getting the camshaft sensor and encoder wheel replaced should provide you with a lasting solution. Since the repair, my car starts reliably and maintains stable idle, even during cold weather.

After getting multiple opinions and your helpful feedback, I finally got the repair done yesterday. The shop confirmed it was indeed the camshaft sensor and worn encoder wheel causing the stalling and engine misfire issues. They completed the work in about 4 hours. The total bill came to 720 Euro, which included the parts and labor. While not cheap, the difference in how the car runs is incredible. No more check engine light, smooth idle, and perfect cold starts. The mechanic showed me the old parts, and the encoder wheel was visibly worn. Really glad I got this sorted before it could cause additional engine damage. The shop also did a thorough diagnostic check to ensure no other sensors were affected. Based on their inspection, this should definitely be a long-term fix.