BMW X7 Rough Idle Points to Faulty Coils

I had nearly identical issues with my 2017 BMW X5 40i last spring. The symptoms you're describing match exactly what I experienced, rough idle, hesitation during acceleration, and the CEL was definitely on. Took it to my mechanic and it turned out to be both faulty ignition coils and spark plugs. The diagnostic showed misfiring on cylinders 2 and 4. The connection between the coils and the wiring harness was also corroded, which made the problem worse. This isn't typically a major repair, but it's crucial to fix it promptly to prevent damage to your catalytic converter. My mechanic showed me how the old coils had visible wear on the boots and connections. Just make sure they check the wiring harness connections too, sometimes it's not just the coils themselves. And definitely get all coils replaced at once, even if only some are failing. It's better preventive maintenance. By the way, your mileage is pretty high for a 2020, so this type of wear is not unusual. Hope this helps with your decision.

Thanks for sharing your experience with the X5! That definitely sounds similar to what I'm dealing with. Just curious, do you remember roughly what you ended up paying for the whole repair? Also, have you had any other ignition-related issues pop up since getting it fixed?

Hey there! Just wanted to follow up on your question. After getting my X5 fixed, I haven't had a single ignition-related problem, it's been running like a dream! The repair wasn't as painful on the wallet as I initially feared. For the defective ignition coil issue, I paid 95 € to fix the faulty cable and plug connections. Turned out it was just the one coil that was acting up, and the mechanic spotted it right away. The best part is that once they sorted out that dodgy connection, all those annoying symptoms, you know, the rough running and stalling, completely disappeared. The engine's been purring like a kitten since then. I'm actually really glad I didn't put off getting it checked, as these things can snowball if left too long. Quick tip though, make sure they do a proper diagnostic first. In my case, they initially thought it might be multiple coils, but it was just the one bad connection causing all the drama. Saved me some money there!

Thanks so much for the detailed follow-up! I actually bit the bullet and took my X7 to a mechanic yesterday. You were spot on about getting it checked quickly. Turns out I had two faulty coils and some corroded connections too. The whole thing cost a bit more than yours since I needed multiple coils replaced, but honestly, it was worth every penny. The mechanic was really thorough and even showed me the worn-out parts, could see exactly why my engine was struggling. He did a full diagnostic first, just like you suggested, which helped pinpoint the exact issues. The best part? My car's running beautifully now, no more rough idling or stalling. It's like driving a completely different vehicle! Really appreciate your help in pushing me to get this sorted. Sometimes you just need that extra bit of reassurance from someone who's been through the same thing. Thanks again for sharing your experience, it really helped me make the right call!