T-Roc Diesel: Rough Engine & Drift Issues Fixed Here

Had the same symptoms on a T-Cross diesel from 2018. With some experience working on cars, I first suspected fuel system issues when the engine started running rough and throwing error codes. After system reset attempts failed to resolve the problem, I took it to a workshop. Their diagnostic testing revealed a faulty fuel injection valve that was causing irregular fuel delivery. The onboard diagnostics confirmed issues with quantity drift compensation values being out of normal range. The repair involved: Complete diagnostic scan, Removal and testing of fuel injectors, Replacement of one defective injector, Fuel injection system calibration, Reset of drift compensation values, Final performance testing Total cost was 515€ including parts and labor. The repair completely resolved the rough running and error codes. To provide more specific advice about your case: Which error codes is your system showing? Are you experiencing any power loss or excessive smoke? Has fuel consumption increased noticeably? When did symptoms first appear, gradual or sudden? Looking forward to providing more targeted suggestions based on your specific situation.

Last service completed at 129000km. The error codes in my case are showing P0401 and P2002, which seems potentially worse than your situation. The symptoms started gradually over the past month, though power loss has been minimal. Fuel consumption increased by roughly 0.8L/100km. After checking the airflow sensors and running additional onboard diagnostics, it looks like recalibrating the fuel injection system might be necessary before attempting any reset procedure. Was your repair covered under warranty? My local workshop quoted 690€ for a similar repair scope. What diagnostic tools did your workshop use to identify the specific injector that was faulty? And did they recommend any preventive maintenance for the other injectors?

Thanks for providing those details about your situation. My repair wasnt covered under warranty since my T-Cross was just past the coverage period. The higher quote you received at 690€ actually sounds reasonable given the complexity of diagnosing and repairing these systems. In my case, the workshop used specialized fuel injection diagnostic equipment to test injection patterns and perform compensation adjustment measurements. They specifically used a high-pressure fuel system analyzer that could measure precise fuel delivery rates and timing for each injector. While only one injector needed replacement in my case, they recommended cleaning all injectors to ensure optimal fuel economy and prevent future drift compensation issues. I declined the additional service at the time but wish I had done it since I had to go back 6 months later for similar symptoms with another injector. Your P0401 and P2002 codes suggest exhaust gas recirculation and particulate filter performance issues, which could be related to the fuel system problems. These often require more extensive performance tuning beyond just injector replacement. I would recommend: 1. Having all injectors tested and cleaned 2. Full system diagnostics including airflow sensors 3. Complete drift compensation reset after repairs 4. Post-repair performance validation testing The slightly higher repair cost could save money long-term by addressing all potential issues at once rather than fixing them piecemeal.

Thanks for the comprehensive replies about the injection system issues. Given the error codes and symptoms described, I will proceed with the full diagnostic service even at the higher 690€ price point. The fuel economy impact alone makes it worth addressing properly. My situation does sound more complex with the P0401 and P2002 codes potentially indicating wider system issues. Will have them check all injectors and complete the recommended preventive maintenance this time. Learning from your experience of having to return for another injector problem, it makes sense to be thorough now. Have scheduled the repair for next week. They will use their fuel system analyzer to properly diagnose the injection patterns and drift compensation values. Will insist on post-repair validation testing to ensure all systems are performing correctly. Really appreciate the detailed explanations about the diagnostic process and repair recommendations. Will update once the work is completed to share what they find and how it gets resolved.