BMW 3 Series Stalling & Emergency Mode: Tank Valve Issue?

Hey there! I have some experience working on BMWs. Had a similar issue with my 2016 BMW 5 Series last year. The symptoms you're describing sound very familiar, I also got the check engine light and stalling problems. Took it to my trusted workshop where they found clogged hoses in the ventilation system. The fix was pretty straightforward, but it took them a few hours to clean everything up and replace some parts. Total bill came to about 175 Euro. Before I can give you more specific advice, could you share: Current mileage? Any other warning lights? When did these symptoms first appear? Have you noticed any fuel smell? By the way, if it helps, my mechanic mentioned this is pretty common in this series of BMWs, especially as they age. Let me know those details and I might be able to share more relevant info from my experience.

Thanks for your detailed response! My car's at 125650 KM and just had its service last month. Actually, I started noticing these symptoms about two weeks ago. No fuel smell thankfully, but I've got the engine malfunction light showing up alongside the check engine light. It's a bit concerning since the car was running perfectly fine before this. It's really helpful to know you had a similar experience and got it sorted, gives me hope it's not something catastrophically expensive. Did your car also have that sudden drop in power when the issue occurred? Think I'll get it checked out by a mechanic soon, just wanted to get some real-world feedback first.

Hey again! Yes, I totally remember having that sudden power loss, it's really unnerving when it happens! My 5 Series would just nose-dive in performance, especially when I needed that extra kick for overtaking. I actually had the exact same experience with the warning lights combo you're describing. The engine malfunction light showing up alongside the check engine light was what pushed me to get it checked out quickly. With your mileage being pretty close to what mine was when this happened (I was at around 130K km), it's looking more and more like we had the same issue. One thing I forgot to mention in my previous reply, before getting it fixed, my car would sometimes run fine for a few days and then suddenly act up again. It was super frustrating! The cleaning and replacement of those ventilation system parts really did the trick though. Haven't had any issues since. Since you've just had your service done, definitely mention that to the mechanic. Could be something they overlooked, or maybe something that developed right after. The good news is that if it's the same problem I had, it's not going to break the bank to fix. Keep us posted on what you find out at the workshop. Always curious to hear if these cases turn out to be similar!

Thanks so much for sharing your experience, it's really reassuring to hear that you went through the same thing and got it fixed without major drama! What you mentioned about the car running fine some days and acting up on others is exactly what I'm experiencing. It's driving me crazy! I've already called my mechanic and booked it in for tomorrow morning. Definitely feeling more confident now that it's likely just those ventilation system issues rather than something more serious. You're right about the power loss being unnerving, especially on busy roads. I'm really hoping the fix will be as straightforward as yours was. The fact that your car's been running smoothly since the repair is super encouraging. Will save your notes about the clogged hoses to discuss with my mechanic, might help speed up the diagnosis. I'll update you once I get the verdict from the workshop. Really appreciate you taking the time to share your experience in such detail. It's made me feel a lot better about the whole situation!