BMW 2 Series: Engine Power Loss & Speed Issues Troubleshoot

Hey there! I have some experience working on cars and had a very similar issue with my 2018 BMW 3 Series (also gas engine). The symptoms you're describing sound exactly like what I experienced last year. My car was showing the same issues, check engine light, power loss, and those annoying speed fluctuations. Turned out it was indeed the crankcase ventilation system that was acting up. Took it to my regular workshop and they confirmed it was defective. The repair, including parts and labor, cost me around 360 Euro, but it completely solved the problem. Now the car runs smoothly again. Before I can share more specific details, could you tell me your current mileage and whether you've noticed any unusual oil consumption or smoke from the exhaust? This would help me give you more targeted advice based on my experience.

Thanks for your detailed response! My car has 118448 KM on the clock and had its last service about 3 months ago. I haven't noticed any unusual oil consumption, but there's occasionally a bit of white smoke when starting up in the morning. The symptoms you described match mine exactly, and it's reassuring to hear you had a similar experience. The repair cost seems reasonable compared to what I was expecting. Did you notice any warning signs before the ventilation system completely failed? I'm trying to determine if I can drive it for another week before taking it to the shop.

Hey again! Thanks for providing those details. Looking at your mileage and symptoms, it's incredibly similar to what I experienced. My 3 Series had around 110000 KM when the issue started. The white smoke you mentioned during cold starts was exactly what I noticed before things got worse. In my case, I did try to keep driving for about a week after the initial symptoms appeared, but honestly, I wouldn't recommend it. The performance kept getting worse, and I was really worried about causing additional damage to the engine. One thing I didn't mention in my first response, I noticed the symptoms were particularly bad during highway driving and when accelerating. The speed fluctuations became more pronounced over time, which made me pretty nervous. The check engine light also started flashing occasionally, which was when I decided not to push my luck any further. The repair was straightforward and took about half a day. If your experience is anything like mine, I'd suggest getting it checked out sooner rather than later. The symptoms won't improve on their own, and you might risk damaging other components if you keep driving it in this condition. Let me know if you need any other specific details about my repair experience. I've kept all the documentation if you need more info about the exact parts they replaced.

Thanks so much for the follow-up and extra details! You've convinced me not to wait on this repair. Those speed fluctuations are definitely getting worse during highway driving, just like you mentioned, and I really don't want to risk causing more damage to my car. I just called my mechanic and managed to get an appointment for tomorrow morning. It's a relief to know this is likely a straightforward fix and not something more serious. Really appreciate you sharing your experience, it's helped me make a much more informed decision. I'll probably end up spending that 360 or so, but it's worth it to get my car running properly again. Thanks again for all your help!