SQ5 Diesel Problems Point to Faulty Injectors

Had nearly identical issues with my 2021 Q5 diesel last winter. The symptoms match exactly what you describe, rough starts, higher gasoline consumption, and noticeable performance loss. After the engine started running very unevenly, I took it to a workshop where they diagnosed dirty injection valves. The repair involved a thorough cleaning of the injection system and replacement of one particularly problematic valve. Total cost was 515 Euro including parts and labor. The emissions values were also way off before the repair, but everything returned to normal after fixing the injectors. The whole repair process took about 4 hours. Can you share some additional details about your vehicle: Current mileage, Type of fuel typically used, How long have the symptoms been present, Any warning lights on the dashboard, Service history regarding fuel system maintenance This information would help confirm if your situation matches what I experienced and could point toward the best repair approach. Quick tip: Using high-quality fuel and regular fuel system cleaners can help prevent these issues in the future.

Last service was done at 45000KM, just a few months ago. The symptoms started appearing gradually over the past 3 weeks. Using premium diesel fuel exclusively. Check engine light came on yesterday after a particularly rough start. Vehicle shows similar behavior to what you described, these injection system issues make sense given the symptoms. Thanks for sharing the repair details and costs. Will schedule a diagnostic check focusing on the injection system.

Thanks for those details. They confirm my suspicions about the injection system being the culprit. After my repair experience, I learned that even with premium diesel and regular maintenance, injector issues can still develop, especially in our engine type. The check engine light coming on after a rough start is exactly what happened in my case. The gradual onset of symptoms over weeks is also very typical for failing injectors. The performance issues tend to worsen steadily until addressed. The repair resolved all my engine performance problems: the rough idle disappeared, fuel consumption returned to normal, and power was fully restored. Even though the cost was 515 Euro, preventing further engine damage made it worthwhile. Worth noting that during my repair, they found carbon buildup around the injectors, which is common in modern diesel engines even with premium fuel. The technician recommended adding a fuel system cleaner every 10000KM to help prevent future issues with the emissions system. Keep us updated after your diagnostic check. Based on the matching symptoms and similar vehicle specs, I suspect youll get confirmation about the injection system needing attention.

I appreciate all the detailed feedback and repair insights. My mechanic confirmed today its definitely the injection system causing these issues. They found carbon deposits around two injectors, matching exactly what was described. Getting it fixed tomorrow, quoted 490 Euro for cleaning and possible replacement of one injector. The vehicle has been getting worse with more frequent misfires and rough running, so timing is perfect. Really helpful to know the repair solved all the performance issues in your case. Will use fuel system cleaner regularly going forward to prevent future problems. Hopefully this fixes the emissions and power loss problems completely. Will post an update once the repair is done. Thanks for helping identify the problem, saved me time troubleshooting and gave me confidence in the diagnosis.