SQ7 Coil Pack Symptoms Lead to Dangerous Stalling

I had a similar issue with my S6 4.0 TFSI last year, these engines are quite similar. With some experience working on VAG engines, I recognized the classic signs of ignition system problems right away. The check engine light, rough idle, and jerking during acceleration matched my situation exactly. Vehicle diagnostics revealed it was indeed a cable connection issue where the harness meets the coil pack, this can cause intermittent misfires and all the symptoms you described. The repair took about 2 hours and cost 95 Euro for labor and parts. The workshop found a damaged wire in the connector that was causing poor contact. They replaced the entire connection assembly to prevent future issues. After the fix, the engine ran perfectly smooth again with no more stalling or jerking. To better assist with your specific case, could you share: Current mileage on your SQ7, When the symptoms first appeared, Whether the check engine light is solid or flashing, If you notice the symptoms more during cold starts These details would help determine if you are dealing with the same spark plug and coil pack connection issue I experienced. Given the similarities between our engines, it could well be the same root cause.

Symptoms first started at 174477 KM during normal driving conditions. The check engine light started flashing intermittently, particularly when the engine hesitation occurs. After checking with OBD, it shows multiple cylinder misfires. My car was last serviced 3 months ago for regular maintenance, but no ignition coil or spark plug work was done. Thanks for sharing your experience about the cable connection issue. The symptoms sound very similar. I will have this checked before my warranty appointment next week. Hopefully its a straightforward fix like in your case. Did your misfires also show on multiple cylinders? And did you have to get all the connectors replaced or just the damaged one?

Thanks for the additional details about the misfires. In my case, the vehicle diagnostics initially showed multiple cylinder misfires too, which made sense given the harness connection issue affecting the whole ignition system. The workshop actually recommended replacing all ignition coil connectors since they were showing signs of wear. Given the mileage and age of the car, this was a sensible preventive measure. The complete set of connectors cost about 180 Euro including labor. Seeing multiple cylinder misfires on the diagnostic scan often points to a common underlying issue rather than individual coil failures. While a single ignition coil can definitely fail, having problems across multiple cylinders typically suggests either a wiring harness issue or a system-wide problem. The flashing check engine light during hesitation is particularly telling, that matches exactly what I experienced before the repair. This usually indicates active misfires severe enough to potentially damage the catalytic converter. Since your car shows such similar symptoms and diagnostic codes to what I dealt with, I strongly suspect you have the same connector degradation issue. Make sure the technician checks the entire ignition coil harness system, not just individual components.

The symptoms and diagnostics you shared match my situation perfectly. Having the confirmation that a flashing check engine light combined with multiple cylinder misfires typically points to a wiring harness issue is really helpful. It makes complete sense to check and potentially replace all ignition coil connectors rather than just fixing one, especially given my mileage. While the 180 Euro cost seems reasonable for a complete connector set replacement, I am glad this will be covered under warranty in my case. I will make sure to mention your experience with the harness connection failures to the technician next week. The vehicle diagnostics showing problems across multiple cylinders rather than isolated coil failure does suggest a system-wide issue, just as you described. I will update the thread once I get the car checked and repaired. Hopefully it will be a straightforward fix like in your case. Having this information beforehand really helps me feel more confident about the upcoming service appointment.