BMW 8 Series Stalling: Tank Ventilation Valve Issue?

I have some experience with cars and had a very similar issue with my 2016 BMW 7 series. The symptoms were exactly like yours, stalling at idle, limp mode, and that annoying check engine light. Took it to my regular workshop and turns out the hoses were completely clogged, restricting proper ventilation. The fix cost me around 175 Euro, but it's been running perfectly since then. The mechanic flushed and cleaned the entire system. What's your current mileage and have you noticed any fuel smell or decreased fuel efficiency? These details would help determine if you're facing the same problem. Also, are there any other warning lights showing up?

Thanks for sharing your experience! My car has 30556 KM on it and just had its service last month. I've definitely noticed the fuel efficiency drop over the past few weeks, and there's occasionally a faint fuel smell when parked. No other warning lights besides the check engine light though. Your situation sounds very similar to what I'm experiencing. Did the cleaning process take long at your workshop? I'm thinking of getting mine checked out soon since it's becoming quite annoying, especially with the unusual stalling at traffic lights.

Hey again! Yeah, the cleaning process for my 7 series took about 2-3 hours total. The mechanics had to remove several components to properly access and clean the ventilation system. Trust me, it's worth getting it done soon, those unusual stalls can be really nerve-wracking, especially in traffic! The fuel smell and decreased efficiency you mentioned are exactly what I experienced too. With similar mileage as well. It's interesting that you had your service last month, sometimes these issues can develop pretty quickly, even right after a service. When I had mine fixed, they showed me the gunk that had built up in the hoses, it was pretty shocking actually. Since the cleaning, I haven't had a single stall, and the fuel efficiency went back to normal. Just make sure they do a thorough job with the cleaning and check all the connected hoses. Quick tip from my experience, after they fix it, keep an eye on your fuel efficiency for the next few weeks. If it doesn't improve, there might be something else going on. But given how similar your symptoms are to what I had, I'm pretty confident it's the same issue. Let us know how it goes after you get it checked out!

Thanks so much for all the detailed info! Really helpful to hear about your experience, especially about the cleaning time and what to expect. I've actually just booked my car in for tomorrow morning, better to get it sorted sooner rather than later. It's quite reassuring to know that after the fix, your car went back to running normally. Will definitely keep track of the fuel efficiency as you suggested. I'm hoping it's just clogged hoses like in your case. The 2-3 hour timeframe works perfectly with my schedule too. I was worried it might be something more serious that would need days to fix. Never thought I'd be so interested in gunked-up hoses, but I'm actually curious to see what they find in mine now! Will update the thread once it's fixed. Thanks again for taking the time to share your experience, it's made me feel a lot more confident about getting this sorted.