BMW XM Starting Issues and Misfires, Fix Needed

Had the exact same symptoms with my 2019 BMW X7 last winter. Started with sluggish performance, then misfiring, and finally got harder to start. Turned out it wasn't the camshaft sensor, it was a combination of bad ignition coils and worn spark plugs. Took it to my regular mechanic and they diagnosed multiple cylinder misfires. Had to replace three coil packs and all spark plugs. Not a super serious repair but definitely not something you want to ignore, as it can damage your catalytic converter if left unchecked. For your XM, I'd suggest getting those coils and plugs checked first before jumping to camshaft sensor conclusions. The symptoms match perfectly with what I experienced. Honestly, it's a pretty straightforward fix if that's what it turns out to be. I know you're hesitant after your last garage experience, but this isn't something you want to leave unaddressed. The engine performance will just keep getting worse.

Thanks for sharing that info about your X7! That's super helpful since I'm dealing with pretty much identical issues. I'll definitely get those coils and plugs checked out first, makes total sense now that you mention it. If you don't mind me asking, do you remember roughly how much you ended up paying for the whole repair? Also, has everything been running smoothly since you got it fixed, or have you noticed any other issues pop up? Thanks again for the advice!

Actually, I need to correct my earlier response about the coils and plugs. I took my X7 back to the mechanic last week, and it turned out the real culprit was indeed the camshaft sensor, exactly what you initially suspected! They found a damaged cable connection to the sensor that was causing all those problems. The repair was pretty straightforward and cost me 95 € to fix the faulty connection. Since then, my car's been running like a dream, no more starting issues, no misfires, and the engine's back to its usual powerful self. It's like driving a completely different car now. Really glad I got it sorted, and honestly, it was a much simpler fix than the coils and plugs would have been. Sometimes the most obvious answer is the right one! Let me know if you get yours checked out, I'd bet money you're dealing with the same issue I had.

Just wanted to update everyone. Finally got the nerve to take my XM to a different mechanic this time. Got it checked out and guess what? The diagnosis threw me for a loop. Turned out to be a dirty fuel injector system and some bad wiring, totally different from what we thought! The mechanic cleaned out the entire fuel system and fixed the wiring harness. Cost me a bit more than expected, but the car's running great now. No more rough starts or misfires. The engine's got its punch back too. Really appreciate everyone's input here, even though my issue ended up being something else entirely. At least I found a decent mechanic this time who took the time to properly diagnose the problem instead of just throwing parts at it. Sometimes you just need to bite the bullet and get things checked out properly, even after a bad experience. Guess that's another lesson learned in car ownership! Thanks again for all the suggestions.