Seat Ibiza Diesel Engine Problems

Poor starting, increased fuel consumption, and rough idling on a diesel Seat Ibiza could point to a few things. Given the mileage, have you considered issues with the diesel particulate filter (DPF) or perhaps the EGR valve? These can definitely impact performance and emissions, sometimes mimicking injector problems. Any recent work done on the car?

DPF or EGR? Interesting. I thought those usually threw up warning lights. Wouldn't a diagnostic tool pinpoint those? I'm just wondering, before I potentially waste money, is there a way to be absolutely sure it's the injectors?

I understand your concern about throwing money at the wrong problem. While DPF and EGR issues can present differently, a faulty injector aligns with your symptoms, particularly the rough idle and potential stalling. Given the car's age and mileage, it's certainly plausible one or more injectors are failing. Before replacing them yourself, consider having a workshop perform a leak-off test and injector balance test. This will definitively confirm if they are the culprit. Continuing to drive with a bad injector can damage the engine and increase emissions, so it's best to get it checked professionally.

Took the Ibiza to the workshop as you suggested. They confirmed it was a dodgy injector. 515€ later, it's running like a dream. Thanks for the advice!