T-Roc TDI Power Loss Points to Cylinder Issues

Had a similar issue with my 2017 T-Cross 2.0 TDI. The symptoms you describe match exactly what I experienced, power loss, high consumption, and rough running. Based on some experience working on TDI engines, I can share what happened in my case. The root cause was actually traced back to a previous intake manifold repair that wasnt done properly. This created an air leak that affected cylinder pressure. The turbocharger wasnt getting proper pressure signals, leading to irregular fuel delivery. Since it was a consequential error from the previous repair, the workshop fixed it at no cost. The fix involved: Complete diagnostic scan, Pressure testing of the intake system, Resealing the intake manifold properly, Checking turbocharger actuator function, Testing cylinder compression Before suggesting more specific solutions, could you share: Current mileage? When was the last major service done? Any recent repairs or maintenance? Are there any other warning lights besides check engine? Any unusual sounds, especially under acceleration? This info would help determine if your issue matches what I experienced with the intake system or if its something else affecting the cylinder pressure.

Thanks for sharing your experience. My current mileage is 146437km and last major service was performed 3 months ago, where they mainly did oil and filter changes. The engine knocking sound is most noticeable during acceleration, and its definitely more pronounced than normal TDI noise. The crankshaft position sensor warning also appeared recently in addition to the check engine light. The timing belt was changed at 120000km, and no major repairs since then. Been monitoring the coolant level closely, no visible loss or mixing with oil, which hopefully rules out head gasket failure. Based on your intake manifold experience, I checked for obvious air leaks but couldnt spot any. The turbo seems to spool normally, though power delivery is inconsistent. Wondering if I should check the camshaft position sensor as well, given the rough running symptoms.

Thanks for providing those details. The additional crankshaft position sensor warning actually points to a different issue than what I experienced with my intake manifold. After hearing about the engine knocking during acceleration and considering the mileage, this sounds more like a fuel delivery problem. In my case, when the engine knocking began getting worse, I discovered worn fuel injectors were the culprit. The inconsistent fuel spray pattern was causing uneven combustion, leading to the knocking and power issues. The diagnostic revealed: Fuel injectors were creating irregular spray patterns, Carbon buildup on piston rings causing compression issues, Crankshaft sensor giving false readings due to the rough running The fix included: Replacing all fuel injectors, Cleaning carbon deposits, New crankshaft position sensor, Full system diagnostic Total repair cost was around 1200€ and took 2 days to complete. The knocking disappeared completely and power returned to normal. Given your symptoms match my experience almost exactly, I would suggest getting the fuel injection system checked first before exploring other possibilities. One quick test: try listening near the fuel injectors while someone revs the engine. Uneven clicking sounds often indicate injector problems.

Thanks for the input. After doing the listening test suggested, I definitely heard uneven clicking from the injectors. The fuel injector theory makes a lot of sense given all my symptoms, the engine knocking, power loss, and sensor warnings. Made an appointment with my workshop for next week. Will have them focus on the injection system first, particularly checking injector spray patterns and timing. The 1200€ cost estimate helps set realistic expectations for the repair budget. Given the mileage and symptoms, replacing all fuel injectors seems like the most logical path forward. The piston rings might need inspection too since carbon buildup could explain the rough running. At least the head gasket seems fine based on my coolant checks. Will update once I get the final diagnosis and repair completed. Really hoping its just the injectors and not something more serious with the engine internals.