BMW Z4 Running Rough? PCV Valve Could Be The Culprit

Hey there! I had a similar issue with my 2012 BMW 335i about 8 months ago. I have some experience working on cars, mainly basic maintenance stuff. The symptoms you're describing sound exactly like what I dealt with. My car was struggling with power delivery, and the engine light was definitely a wake-up call. Took it to my regular workshop, and they confirmed it was indeed the crankcase ventilation system that was acting up. The repair set me back about 360 Euro, but it was worth it, car's been running smooth since then. Interesting you mention the Z4, I've heard they can have similar issues to the 3 series when it comes to the ventilation system. Could you share more details about your mileage and whether you've noticed any oil consumption or unusual smoke from the exhaust? This info would help confirm if we're looking at the same problem. Have you noticed any rough idling or weird noises when accelerating?

Thanks for sharing your experience! My Z4 is currently at 42463 KM and just had its service last month. Yeah, I've definitely noticed rough idling, especially when cold, and there's a subtle rattling noise during acceleration. Haven't seen any unusual smoke yet, but fuel consumption seems a bit higher than usual. Getting it looked at tomorrow, but your experience with the ventilation system repair is really helpful, gives me a good idea of what to expect cost-wise. The symptoms matching up definitely makes me feel more confident about what might be wrong. Did your car take long to fix when you got it repaired?

Hey again! Yeah, my 335i repair was pretty straightforward, took the shop about 4-5 hours total. The symptoms you're describing are spot-on with what I experienced. That rattling noise during acceleration? Had exactly the same thing, and it drove me nuts before I got it fixed. Since you mentioned your Z4's recent service and the mileage, it's worth noting that these ventilation issues can pop up regardless of maintenance, just one of those BMW quirks we deal with. My car had similar mileage when it happened too. The rough cold idle is a classic sign, that's how mine started. The good news is, once they fixed the ventilation valve, all these symptoms cleared up completely. The fuel consumption went back to normal too, which was a nice bonus for my wallet. Quick tip though, make sure they check the valve's connecting hoses while they're at it. Sometimes they can get brittle and cause similar issues. Found that out the hard way when I had to go back a month later for a cracked hose. Live and learn, right? Let me know how it goes at the shop tomorrow. Always curious to hear if others' experiences match up with mine.

Thanks so much for the detailed follow-up! That's super helpful to know about the repair time, 4-5 hours isn't too bad at all. I'll definitely mention the connecting hoses to my mechanic tomorrow. Really don't want to deal with a second trip if they get overlooked! It's actually really reassuring to hear that your symptoms were so similar and that fixing the ventilation valve sorted everything out. The fuel consumption thing has been bugging me, so it's good to know that should improve too. Funny how these BMWs seem to have their own mechanicality with these quirks! I'll make sure to update you after the shop visit tomorrow. Really appreciate all your insights, helped me feel way more prepared for what to expect. At least now I won't be totally shocked when they hand me the bill! Thanks again for taking the time to share your experience.