BMW Z4 Misfire & Power Loss: Camshaft Sensor Issue?

Hi there! I've got some experience working on BMWs, I'd say low to moderate expertise level. I actually faced a similar issue with my 2020 BMW M2 last year. The symptoms were almost identical to what you're describing. After taking it to my trusted workshop, they found that the wiring connection to the camshaft position sensor was damaged, causing intermittent signal issues. The repair involved replacing the wiring harness and connector, cost me around 95 Euro to fix. The symptoms cleared up right away, and the car's been running smoothly since then. Could you share some additional details about your Z4? Like: What's the exact fault code you're getting? Does the issue happen more when the engine is cold or warm? Have you noticed any changes in fuel consumption? This would help me give you more specific advice based on my experience.

Thanks for sharing your experience! My Z4's still pretty new with only 20596 KM on the clock, and I just had it serviced last month. The issue tends to happen more when the engine's cold, especially during morning starts. Haven't really noticed any significant change in fuel consumption though. The fault code I'm getting is P0340. Makes me think your diagnosis about the wiring connection could be spot-on. Was your repair covered under warranty? Since mine's a 2022 model, I'm hoping I can get this sorted under warranty rather than paying out of pocket. Really appreciate the help! Let me know if you need any other details.

Hey again! Thanks for the follow-up. Really glad to hear you got back with those details. Actually, in my case, the warranty had just expired when the issue came up (talk about bad timing!). That's why I had to pay for the repair out of pocket. But with your 2022 Z4, you should definitely be covered under warranty, BMW's new vehicle warranty is pretty solid for these kinds of issues. The P0340 code and those cold-start symptoms sound exactly like what I experienced. The fact that it's happening mainly during cold starts without affecting fuel consumption really points to that wiring connection issue I had. Quick tip from my experience, while you're waiting to get it to the dealer, try to avoid multiple start attempts when it's acting up. I made that mistake and it put extra stress on the starter motor. Just give it a moment if it doesn't start right away. You might want to document when these issues occur (time, temperature, etc.), it helped speed up the diagnosis process when I took mine in. The more info you can give them, the better. Have you already scheduled an appointment with your dealer? Let me know how it goes, I'm curious if they find the same issue as mine.

Thanks so much for your detailed response! You're absolutely right about documenting everything, I've actually started keeping notes on my phone every time it acts up. Just got off the phone with the dealership and managed to get an appointment for next week. Really helpful tip about avoiding multiple start attempts, I've definitely been guilty of that! Will make sure to be more patient with it until I can get it looked at. The fact that your M2 had such a similar issue is reassuring, at least it seems like a known problem with a straightforward fix. The service advisor mentioned they've seen a few similar cases, so fingers crossed it's just that wiring connection like in your case. The car being under warranty is definitely a relief, wouldn't want to deal with unexpected repair costs on such a new vehicle. I'll update you once I get it checked out. Thanks again for taking the time to share your experience, it's been super helpful in understanding what I might be dealing with!