BMW 1 Series DPF Failure, Symptoms and Solutions

Hey there! I have some experience working on cars and went through something very similar with my 2012 BMW 3 Series diesel. Initially thought it was the DPF itself, but it turned out to be just the exhaust back pressure sensor playing up. Had the same symptoms, warning lights, drop in power, and that nasty smoke. Took it to my regular workshop and they diagnosed it properly. They replaced the faulty sensor, which set me back about 245 Euro including labor. Since then, everything's been running smoothly, no more warnings or power issues. What's your mileage and have you noticed any other warning lights? Also, does the smoke color change during different driving conditions? These details would help confirm if you're dealing with the same issue I had. BTW, if it helps, my owns a 2014 BMW 2 Series and swears by regular DPF regeneration cycles, might be worth checking if yours is completing them properly.

Thanks for sharing your experience! My car has 157629 KM and had its last service about 2 months ago. The smoke is definitely darker during acceleration, but it's more grayish when idling. I'm really hoping it's just the sensor like in your case, that would be a much cheaper fix than replacing the entire DPF. Haven't noticed any additional warning lights besides the DPF one. The car still runs, but it's definitely not happy, especially when accelerating. Think I'll get it checked out this week before it gets worse.

Hey again! Just wanted to follow up on this since you mentioned the smoke color and mileage. Your symptoms sound exactly like what I experienced, that grayish to dark smoke pattern is really familiar. After my sensor fix that I mentioned earlier, I actually had to deal with this again at around 160,000 KM (pretty close to your mileage). Same symptoms came back, but this time it actually was the DPF getting clogged. The sensor wasn't lying that time! My mechanic suggested doing a forced DPF regeneration first, which helped temporarily but didn't solve the issue completely. Ended up needing a thorough DPF cleaning service. Cost more than the sensor replacement I told you about before (around 400-450 Euro), but it was still better than a full DPF replacement. Since then, I've learned to keep an eye on how I drive, mixing up city driving with some good highway runs helps prevent it from happening again. If you're mainly doing short trips, that could be why your DPF isn't regenerating properly. Let me know what your mechanic says. Given how similar our situations are, I'm really curious to know if you're dealing with the same thing I did.

Thanks so much for the detailed follow-up! Just got back from checking the car again and you might be right about the DPF regeneration thing. I've been doing lots of short trips lately, which probably isn't helping. Makes total sense about mixing in highway driving, haven't done much of that recently with working from home. Your experience with the forced regeneration and cleaning is super helpful. Honestly, 400-450 for a cleaning sounds way better than what I was imagining, was worried I'd be looking at a complete DPF replacement which I've heard can cost a fortune. Got an appointment scheduled with my mechanic for tomorrow morning, and I'll definitely ask about both the sensor and cleaning options you mentioned. Good tip about the driving patterns too, guess I need to take the car out for some proper runs more often! Will definitely let you know what the mechanic finds. Really appreciate all the help and sharing your experience, it's made me feel a lot less worried about the whole situation!