BMW X6 Diesel: Misfires & QDC Issues, Help Needed!

Hi! I have some experience with cars and went through something very similar with my 2020 BMW X5 diesel last year. The symptoms were exactly what you're describing, rough running, misfires, and that annoying check engine light. Turned out one of the injectors was faulty and needed replacement. Took it to my regular workshop, and they confirmed it after running diagnostics. Total bill came to 515 Euro, not cheap, but it fixed the issue completely. Haven't had any problems since then. I've heard similar issues with other X-series BMWs too. Before jumping to conclusions though, could you share: How many miles/kilometers on your X6? Are you getting any specific error codes? Have you noticed any loss in power or increased fuel consumption? This would help me give you more specific advice based on what worked in my case.

Thanks for your detailed response! My X6 has 73609 KM on the clock and had its last service about 3 months ago. I've definitely noticed increased fuel consumption lately, about 15% more than usual. The error code I'm getting is P0263, which points to the first cylinder injector circuit. What's interesting is that the issue seems worse during cold starts, but somewhat improves once the engine warms up. Did you experience something similar with your X5? The cost you mentioned for the injector replacement seems reasonable, I was actually expecting worse. Did they replace just the one injector or did they suggest doing all of them? I've booked it in at the workshop for next week, but wanted to gather some more info from fellow BMW owners before going in. Really appreciate your help!

Hey again! You know what? Your symptoms sound exactly like what I dealt with on my X5! That same error code, P0263, and the cold start issues were like déjà vu. Mine also had that weird thing where it ran better once warmed up. In my case, they initially just replaced the faulty injector (cylinder 1), but my mechanic did mention that sometimes it's worth doing all of them while you're in there. I decided to stick with just the one since mine had similar mileage to yours and the other injectors tested fine. Been running smooth as silk since then. Quick tip from my experience, make sure they properly code the new injector to the ECU. My workshop initially forgot this step and it took another visit to get it sorted. The fuel consumption went right back to normal after everything was properly set up. Keep us posted on what your workshop finds! Based on how similar our issues are, I'd bet you're looking at the same fix. Just make sure they do a proper diagnostic first, don't let them just assume it's the injector without testing thoroughly like they did with mine. Let me know how it goes next week, really curious to hear if it's the same issue!

Thanks so much for sharing your experience! It's really reassuring to know someone else dealt with exactly the same issue. I'll definitely make sure to mention the ECU coding to my mechanic, that's a great tip I wouldn't have thought about. I've actually just called the workshop and specifically asked them about the diagnostic process and coding requirements. They seemed knowledgeable and confirmed they'll do comprehensive testing before replacing anything. They also mentioned they stock original BMW injectors, which gives me some peace of mind. I'll definitely update you once it's fixed. Based on how identical our symptoms are, I'm feeling much more confident about the repair now. Really appreciate you taking the time to share all this detailed info, it's exactly what I needed to know before heading to the workshop!