BMW 8 Check Engine + Power Loss: PCV Valve Issue?

Hey! I had some experience with a similar issue on my 2021 BMW 7 Series (also have a 5 Series). I'd say I have some experience working with cars, but I'm no expert. The symptoms you're describing sound exactly like what I dealt with. My check engine light came on, and the car felt sluggish with inconsistent power delivery. Took it to my regular workshop, and they diagnosed a faulty crankcase ventilation system. The fix cost me about 360 Euro, including parts and labor. They had to replace the valve and some connecting hoses. Car's been running smoothly since then. What's your mileage, and have you noticed any unusual engine sounds or smoke from the exhaust? This info would help me share more relevant details about my experience.

Thanks for sharing your experience! My BMW 8 just had its latest service but started showing these symptoms shortly after. I've got 134948 KM on the clock now. Come to think of it, I haven't noticed any unusual sounds or smoke, just the power issues and that annoying check engine light. Good to know your fix was relatively straightforward, sounds like I might be dealing with the same thing. Think I'll get it checked out by a mechanic soon before it gets worse. Did your car throw any specific error codes when you had this issue?

Yeah, absolutely! When I had this issue with my BMW 7, it actually threw the P0171 code (System Too Lean) which my mechanic picked up during the diagnostic. Looking back, it was pretty similar to what you're experiencing, mine started acting up right after a regular service too, which was kind of frustrating. Since you mentioned your mileage is around 135k, that's actually pretty close to when mine started showing these symptoms (I was at about 128k). The good news is that once I got it fixed, it really was like night and day difference. The power came back immediately, and that annoying check engine light finally went off. Just a heads up though, I'd recommend getting it checked soon. I waited around for about two weeks after the symptoms started, and while nothing catastrophic happened, my fuel economy took a pretty noticeable hit during that time. The repair itself was pretty quick, my car was in and out of the shop in about 3 hours. Let me know how it goes when you get it checked out. I'm curious if it turns out to be the same issue. These BMWs can be a bit finicky sometimes, but they're worth the occasional headache!

Thanks so much for all the detailed info! That P0171 code definitely gives me something specific to mention to my mechanic. It's funny how similar our situations are, even down to the timing after the service. I've actually noticed my fuel consumption has gone up too, now that you mention it. I'm going to call my mechanic first thing tomorrow and get it booked in. Better to sort it out now than let it drag on and potentially cause more problems. Really appreciate you taking the time to share your experience, it's made me feel a lot more confident about what I might be dealing with. I'll probably only be out of pocket about the same as you were, which isn't too bad for a BMW repair! I'll definitely update you once I get it sorted. These cars really are worth the occasional hassle, aren't they?