BMW X4 Cold Start Nightmare: Injector or Something More?

I had almost identical symptoms with my 2018 BMW X3 last winter. The rough idle and hard starts were a real pain, especially on cold mornings. Turned out to be a faulty fuel injector in cylinder 2. When I took it to the garage, they ran diagnostics and found the injector wasn't atomizing fuel properly, causing uneven fuel distribution. It was pretty serious since bad injectors can damage other engine components if left unfixed. My mechanic showed me how the old injector had carbon buildup and wasn't opening/closing correctly. They had to replace the problematic injector and clean the others. They also checked the fuel pressure and cleaned the fuel rail while they were at it. The whole job took about a day, but it was worth it. Car starts perfectly now, even in cold weather, and fuel consumption is back to normal. Given your symptoms, especially the excessive fuel consumption during cold starts, I'd definitely get those injectors checked soon. It's not something you want to ignore.

Thanks for sharing your experience! This sounds exactly like what I'm dealing with. Really helpful to know it was the fuel injector in your case. Do you remember roughly how much you ended up paying for the whole repair? Also, has everything been running smoothly since the fix, or have you noticed any other issues pop up?

Hey there! Happy to give you an update. Since I got the faulty cold start injector replaced, my X3's been running like a dream. The total bill came to 515 € for replacing the injection valve, money well spent if you ask me! The repair job was actually pretty straightforward once they identified the problem. Not a single issue since then, starts up perfectly every morning, no more rough idling, and my fuel consumption's back to what it should be. Honestly, it's like having a different car compared to before. The mechanic did a great job explaining everything, and they even showed me the old injector, it was pretty gunked up. If you're experiencing similar symptoms, I'd definitely recommend getting it checked out sooner rather than later. These things tend to get worse (and more expensive) if you leave them too long. Just make sure you find a good mechanic who knows their way around BMW fuel systems. Trust me, it makes all the difference!

Thanks so much for all that detail! I took your advice and finally got my X4 checked out by a BMW specialist. You were spot on, it was indeed the cold start injector causing all the trouble. The mechanic found significant carbon buildup, just like in your case. The repair cost was a bit steeper than expected, but totally worth it. They replaced the faulty injector and did a thorough cleaning of the fuel system. The car's running amazingly now, starts up instantly, even on cold mornings, and the rough idle is completely gone. Such a relief! The mechanic actually showed me the old injector, it was in pretty rough shape. Really glad I didn't wait any longer to get it fixed. Thanks again for sharing your experience, it gave me the push I needed to get this sorted before it turned into a bigger problem!