BMW Diesel Stalling: MAF Sensor or Something Worse?

Hi there! I experienced nearly identical symptoms with my 2009 BMW 3 Series 335d last year. The rough idle, hesitation during acceleration, and increased fuel consumption were exactly what I faced. After scanning, the MAF sensor was indeed the culprit. Had it replaced at the garage since it's a critical component for proper engine function. The faulty sensor was causing incorrect air-fuel mixture readings, which explained all those symptoms. The repair wasn't particularly complex, but ignoring it could've led to more serious engine damage. After replacement, the engine ran smooth again, fuel economy went back to normal, and passed emissions without issues. If your symptoms match this closely, I'd say getting the MAF sensor checked should be your first step. Best of luck with the repair.

Thanks for sharing your experience! That's really helpful and matches my symptoms perfectly. I was worried it might be something more serious. Do you remember roughly how much you ended up paying for the MAF sensor replacement? Also, curious if you've had any other issues pop up since getting it fixed?

Hey again! Great to hear back from you! Just wanted to update that I did get the MAF sensor replaced after my previous reply, and it cost me 365€ all in. Money well spent, I'd say, as my 335d has been running like a dream since the fix. It's like having a completely different car now, no more jerking, stalling, or any of those annoying symptoms we discussed. The best part? Haven't had a single issue since getting it sorted. The engine's running smooth as silk, fuel consumption is back to normal, and those worrying symptoms are totally gone. The repair shop diagnosed it spot on with the faulty MAF sensor, and fixing it resolved all the problems. If your symptoms are matching what I experienced, I'd definitely recommend getting it checked out sooner rather than later. The peace of mind alone is worth it, and you'll save money on fuel in the long run since the engine will be running efficiently again. Feel free to ask if you need any other details about the repair or how it's been performing since!

Thanks again for all the info! I actually took your advice and got it checked out by a new mechanic this week. You were spot on, it was the MAF sensor! Paid about the same as you did for the replacement. The whole repair process was surprisingly quick. The mechanic was really thorough and even showed me the old sensor, explaining how it was affecting the engine. Got the car back yesterday and what a difference! No more stalling, the acceleration is smooth again, and the engine's purring like it should. The best part is seeing my fuel gauge not dropping like a rock anymore. Such a relief it wasn't something more serious. Really glad I asked here and got your input, saved me from stressing out over potentially bigger issues. Thanks for helping me get this sorted!