SQ8 Power Loss Linked to Faulty Camshaft Sensor

As someone with some mechanical experience, I dealt with an identical issue on my 2018 S7. The symptoms you describe match exactly what I experienced, engine light, power loss, and poor fuel economy. The root cause turned out to be a faulty crankshaft position sensor. Had it diagnosed at a workshop and they confirmed the sensor was sending incorrect signals, causing timing issues between the crankshaft and camshaft positions. The repair involved replacing the crank sensor and clearing the fault codes. Total cost was 340 Euro including parts and labor. The issue completely resolved after the repair, no more warning lights, power was restored, and fuel consumption returned to normal. These sensors can fail regardless of vehicle age, and when they do, they typically cause the exact symptoms you mentioned. To better assist with your specific case, could you share: Current mileage, Whether you notice any rough idling, If the engine light is constant or intermittent, Whether you experience any misfires during acceleration This would help confirm if your issue matches what I encountered and could save you time in diagnosis.

As someone with some mechanical experience, I dealt with an identical issue on my 2018 S7. The symptoms you describe match exactly what I experienced, engine light, power loss, and poor fuel economy. The root cause turned out to be a faulty crankshaft position sensor. Had it diagnosed at a workshop and they confirmed the sensor was sending incorrect signals, causing timing issues between the crankshaft and camshaft positions. The repair involved replacing the crank sensor and clearing the fault codes. Total cost was 340 Euro including parts and labor. The issue completely resolved after the repair, no more warning lights, power was restored, and fuel consumption returned to normal. These sensors can fail regardless of vehicle age, and when they do, they typically cause the exact symptoms you mentioned. To better assist with your specific case, could you share: Current mileage, Whether you notice any rough idling, If the engine light is constant or intermittent, Whether you experience any misfires during acceleration This would help confirm if your issue matches what I encountered and could save you time in diagnosis.

As someone with some mechanical experience, I dealt with an identical issue on my 2018 S7. The symptoms you describe match exactly what I experienced, engine light, power loss, and poor fuel economy. The root cause turned out to be a faulty crankshaft position sensor. Had it diagnosed at a workshop and they confirmed the sensor was sending incorrect signals, causing timing issues between the crankshaft and camshaft positions. The repair involved replacing the crank sensor and clearing the fault codes. Total cost was 340 Euro including parts and labor. The issue completely resolved after the repair, no more warning lights, power was restored, and fuel consumption returned to normal. These sensors can fail regardless of vehicle age, and when they do, they typically cause the exact symptoms you mentioned. To better assist with your specific case, could you share: Current mileage, Whether you notice any rough idling, If the engine light is constant or intermittent, Whether you experience any misfires during acceleration This would help confirm if your issue matches what I encountered and could save you time in diagnosis.

As someone with some mechanical experience, I dealt with an identical issue on my 2018 S7. The symptoms you describe match exactly what I experienced, engine light, power loss, and poor fuel economy. The root cause turned out to be a faulty crankshaft position sensor. Had it diagnosed at a workshop and they confirmed the sensor was sending incorrect signals, causing timing issues between the crankshaft and camshaft positions. The repair involved replacing the crank sensor and clearing the fault codes. Total cost was 340 Euro including parts and labor. The issue completely resolved after the repair, no more warning lights, power was restored, and fuel consumption returned to normal. These sensors can fail regardless of vehicle age, and when they do, they typically cause the exact symptoms you mentioned. To better assist with your specific case, could you share: Current mileage, Whether you notice any rough idling, If the engine light is constant or intermittent, Whether you experience any misfires during acceleration This would help confirm if your issue matches what I encountered and could save you time in diagnosis.

Thanks for the insights about the crank sensor. After dealing with these symptoms for about 2 weeks, I finally got it diagnosed. My readings were completely off, showing engine synchronization issues between cam and crank signals. The timing chain tensioner was also making noise on cold starts. Mileage is at 143225 KM, and the last service was just 2 months ago. My fault codes now show multiple misfires across different cylinders, which explains the power loss. The reference values between sensors are way outside spec according to the diagnostic report. Just scheduled a repair appointment, hoping its just the sensor and not a more serious timing chain issue. Anyone know the typical labor hours for sensor replacement on these engines?

Thanks for the insights about the crank sensor. After dealing with these symptoms for about 2 weeks, I finally got it diagnosed. My readings were completely off, showing engine synchronization issues between cam and crank signals. The timing chain tensioner was also making noise on cold starts. Mileage is at 143225 KM, and the last service was just 2 months ago. My fault codes now show multiple misfires across different cylinders, which explains the power loss. The reference values between sensors are way outside spec according to the diagnostic report. Just scheduled a repair appointment, hoping its just the sensor and not a more serious timing chain issue. Anyone know the typical labor hours for sensor replacement on these engines?

Thanks for the insights about the crank sensor. After dealing with these symptoms for about 2 weeks, I finally got it diagnosed. My readings were completely off, showing engine synchronization issues between cam and crank signals. The timing chain tensioner was also making noise on cold starts. Mileage is at 143225 KM, and the last service was just 2 months ago. My fault codes now show multiple misfires across different cylinders, which explains the power loss. The reference values between sensors are way outside spec according to the diagnostic report. Just scheduled a repair appointment, hoping its just the sensor and not a more serious timing chain issue. Anyone know the typical labor hours for sensor replacement on these engines?

Thanks for the insights about the crank sensor. After dealing with these symptoms for about 2 weeks, I finally got it diagnosed. My readings were completely off, showing engine synchronization issues between cam and crank signals. The timing chain tensioner was also making noise on cold starts. Mileage is at 143225 KM, and the last service was just 2 months ago. My fault codes now show multiple misfires across different cylinders, which explains the power loss. The reference values between sensors are way outside spec according to the diagnostic report. Just scheduled a repair appointment, hoping its just the sensor and not a more serious timing chain issue. Anyone know the typical labor hours for sensor replacement on these engines?

Thanks for the update. Just like my S7 case, those sync issues between cam and crank signals are definitely concerning. When I had my sensor replaced, labor time was about 2 hours, but the location of the sensor can vary depending on engine configuration. Given your symptoms are progressing (multiple misfires, timing chain noise), this sounds potentially more complex than my situation. While my fix was just the crankshaft position sensor, the timing chain tensioner noise you mentioned raises some red flags. The engine synchronization problems combined with cold start noise could indicate the timing chain system needs attention. When they did my sensor replacement, total labor was around 180 Euro, but if they need to access the timing chain system, expect significantly more. The diagnostic signs you describe, especially the reference values being far out of spec, match what I experienced, but the cold start noise is an additional concern I didnt have. Would definitely recommend having them check the entire timing system while they have it apart. Much better to address any chain wear now than risk more serious engine damage.

Thanks for the update. Just like my S7 case, those sync issues between cam and crank signals are definitely concerning. When I had my sensor replaced, labor time was about 2 hours, but the location of the sensor can vary depending on engine configuration. Given your symptoms are progressing (multiple misfires, timing chain noise), this sounds potentially more complex than my situation. While my fix was just the crankshaft position sensor, the timing chain tensioner noise you mentioned raises some red flags. The engine synchronization problems combined with cold start noise could indicate the timing chain system needs attention. When they did my sensor replacement, total labor was around 180 Euro, but if they need to access the timing chain system, expect significantly more. The diagnostic signs you describe, especially the reference values being far out of spec, match what I experienced, but the cold start noise is an additional concern I didnt have. Would definitely recommend having them check the entire timing system while they have it apart. Much better to address any chain wear now than risk more serious engine damage.

Thanks for the update. Just like my S7 case, those sync issues between cam and crank signals are definitely concerning. When I had my sensor replaced, labor time was about 2 hours, but the location of the sensor can vary depending on engine configuration. Given your symptoms are progressing (multiple misfires, timing chain noise), this sounds potentially more complex than my situation. While my fix was just the crankshaft position sensor, the timing chain tensioner noise you mentioned raises some red flags. The engine synchronization problems combined with cold start noise could indicate the timing chain system needs attention. When they did my sensor replacement, total labor was around 180 Euro, but if they need to access the timing chain system, expect significantly more. The diagnostic signs you describe, especially the reference values being far out of spec, match what I experienced, but the cold start noise is an additional concern I didnt have. Would definitely recommend having them check the entire timing system while they have it apart. Much better to address any chain wear now than risk more serious engine damage.

Thanks for the update. Just like my S7 case, those sync issues between cam and crank signals are definitely concerning. When I had my sensor replaced, labor time was about 2 hours, but the location of the sensor can vary depending on engine configuration. Given your symptoms are progressing (multiple misfires, timing chain noise), this sounds potentially more complex than my situation. While my fix was just the crankshaft position sensor, the timing chain tensioner noise you mentioned raises some red flags. The engine synchronization problems combined with cold start noise could indicate the timing chain system needs attention. When they did my sensor replacement, total labor was around 180 Euro, but if they need to access the timing chain system, expect significantly more. The diagnostic signs you describe, especially the reference values being far out of spec, match what I experienced, but the cold start noise is an additional concern I didnt have. Would definitely recommend having them check the entire timing system while they have it apart. Much better to address any chain wear now than risk more serious engine damage.

Thanks for the feedback. After getting it properly diagnosed today, turns out its more serious than initially hoped. The timing chain tensioner has failed, causing the engine synchronization issues. The misfire codes were a result of the timing being off, not a simple sensor problem. Total estimate for repairs is 2800 Euro, which includes replacing the timing chain, tensioner, guides and both cam position sensors since they were damaged by the incorrect timing. Labor is quoted at 16 hours since they need to remove the front of the engine to access everything. Going to get it fixed next week, cant risk driving it much with the timing being off. The multiple misfires and bad reference values between sensors make sense now given the chain tensioner failure. Definitely learned my lesson about investigating unusual noises sooner rather than later. Will update once the repair is complete in case anyone else runs into similar issues with their engine.

Thanks for the feedback. After getting it properly diagnosed today, turns out its more serious than initially hoped. The timing chain tensioner has failed, causing the engine synchronization issues. The misfire codes were a result of the timing being off, not a simple sensor problem. Total estimate for repairs is 2800 Euro, which includes replacing the timing chain, tensioner, guides and both cam position sensors since they were damaged by the incorrect timing. Labor is quoted at 16 hours since they need to remove the front of the engine to access everything. Going to get it fixed next week, cant risk driving it much with the timing being off. The multiple misfires and bad reference values between sensors make sense now given the chain tensioner failure. Definitely learned my lesson about investigating unusual noises sooner rather than later. Will update once the repair is complete in case anyone else runs into similar issues with their engine.

Thanks for the feedback. After getting it properly diagnosed today, turns out its more serious than initially hoped. The timing chain tensioner has failed, causing the engine synchronization issues. The misfire codes were a result of the timing being off, not a simple sensor problem. Total estimate for repairs is 2800 Euro, which includes replacing the timing chain, tensioner, guides and both cam position sensors since they were damaged by the incorrect timing. Labor is quoted at 16 hours since they need to remove the front of the engine to access everything. Going to get it fixed next week, cant risk driving it much with the timing being off. The multiple misfires and bad reference values between sensors make sense now given the chain tensioner failure. Definitely learned my lesson about investigating unusual noises sooner rather than later. Will update once the repair is complete in case anyone else runs into similar issues with their engine.

Thanks for the feedback. After getting it properly diagnosed today, turns out its more serious than initially hoped. The timing chain tensioner has failed, causing the engine synchronization issues. The misfire codes were a result of the timing being off, not a simple sensor problem. Total estimate for repairs is 2800 Euro, which includes replacing the timing chain, tensioner, guides and both cam position sensors since they were damaged by the incorrect timing. Labor is quoted at 16 hours since they need to remove the front of the engine to access everything. Going to get it fixed next week, cant risk driving it much with the timing being off. The multiple misfires and bad reference values between sensors make sense now given the chain tensioner failure. Definitely learned my lesson about investigating unusual noises sooner rather than later. Will update once the repair is complete in case anyone else runs into similar issues with their engine.