BMW X4 Misfire Mystery: Camshaft Sensor Suspicions

Hey there! I had some experience with a similar issue on my 2020 BMW X3 (and previously owned an X5). I have some basic car maintenance experience, though I'm no expert. When I faced those exact symptoms, rough starts, misfires, and power loss, it turned out to be a faulty connection in the wiring harness to the camshaft sensor. My trusted mechanic spotted it pretty quickly. The repair involved replacing some corroded wiring and a connector, cost me around 95 Euro and solved the problem completely. Before jumping to conclusions though, what's the specific error code you're getting? Also, has your X4 shown any other symptoms, like increased fuel consumption or check engine light flashing? Having this info would help me share more relevant details from my experience.

Thanks for sharing that experience! Mine's sitting at 66999 KM and just had its latest service last month. Initially thought it might be something major, but your wiring harness mention got me thinking. Been getting the P0340 code, and yeah, definitely noticed the fuel consumption going up lately. The check engine light's been more flickering than steady, which is new. Good to hear your fix was relatively straightforward, gives me hope it won't be too painful on the wallet! Might get it checked by my mechanic this week, just to be safe.

Hey again! Thanks for getting back with those details. You know what's funny? My X3 had almost the same mileage (around 65K) when I ran into that issue. That P0340 code is exactly what I got too! The flickering check engine light and increased fuel consumption, it's like déjà vu. Just be careful though, in my case, I initially tried to save some money by just cleaning the sensor and connections myself, but that only worked for about a week before the problems came back. Ended up having to get it properly fixed anyway. When my mechanic dug deeper, they found that water had gotten into the wiring connector over time, causing intermittent connection issues. That's why the symptoms would sometimes come and go. The whole repair took about 2 hours, and like I mentioned before, wasn't too expensive. Since you've just had your service done, I'd definitely mention that to your mechanic, sometimes these issues can start showing up right after a service if something wasn't connected properly. Better to get it sorted sooner rather than later. Let me know how it goes, really curious if it turns out to be the same issue as mine!

Thanks so much for all that detail, it's super helpful! Just got back from the mechanic actually, and you were spot on. Turns out it was indeed a wiring issue, almost identical to what you described. The connector had some corrosion and water damage, probably from all those car washes I've been getting lately. They found it pretty quickly once I mentioned your experience with the X3. Total repair came to about 120 for parts and labor, which honestly feels like a bargain considering how worried I was initially. They cleaned up all the connections, replaced the damaged wiring and connector, and now she's running smooth as silk. No more flickering lights, rough starts are gone, and the power's back to normal. Really appreciate you taking the time to share your experience, saved me a lot of worry and probably some money too, since I might've ended up replacing the whole sensor otherwise. It's great to know there are other BMW owners out there willing to help out with their experiences!