BMW Diesel DPF Warning: Smoke and Power Loss Issues

Had the same problem with my 2010 BMW 3 Series diesel last year. The symptoms were identical, power loss, smoke during acceleration, and that distinctive exhaust smell. My mechanic found that the exhaust back pressure sensor was completely shot. The faulty sensor was sending wrong readings to the ECU, which messed up the DPF regeneration cycle. Pretty serious issue since it can lead to complete DPF failure if not fixed. The repair involved replacing the pressure sensor and doing a forced DPF regeneration. While they had it open, they also cleaned the EGR valve as a preventive measure. The whole thing took about a day at the garage. Been running smooth since then, no more warning lights or power issues. Just make sure you find a mechanic who's experienced with diesel particulate systems, it's not something you want handled by someone who's guessing.

Thanks for sharing your experience! That's reassuring to hear you had similar symptoms and got it fixed. I'll definitely look for someone who knows their way around DPF systems. Quick question, do you remember roughly how much the repair set you back? Also, has everything stayed problem-free since the fix, or have you noticed anything else pop up?

Hey there again! Yep, just to follow up, I got it all sorted. The repair bill came to 245 € for replacing that faulty exhaust back pressure sensor, and it was money well spent. The mechanic nailed the diagnosis, it was exactly what was causing that low DPF pressure warning. I'm happy to report the car's been running like a dream since the fix. No more warning lights, the power's back to normal, and that annoying smoke during acceleration is completely gone. The exhaust smell has disappeared too. It's been such a relief not having to worry about it anymore. To be honest, I was initially concerned it might be something more serious (and expensive!), but the sensor replacement did the trick. My advice would be to get it checked out sooner rather than later, these DPF issues can get worse if you leave them too long. Let me know how you get on with yours!

Thanks everyone for the helpful responses! Just wanted to update you all on how things turned out. I finally got the car checked at a new mechanic who specializes in diesel engines. They found it was indeed the exhaust pressure sensor causing all the trouble, just like some of you mentioned. The repair wasn't as painful as I'd feared, cost me about 300 bucks including labor. They replaced the sensor and did a DPF regeneration cycle. What a difference it made! The warning light's gone, no more smoke when I accelerate, and that nasty exhaust smell has completely disappeared. The engine's got its punch back too. The mechanic was great, really took the time to explain everything and even showed me the old sensor. Much better experience than my last garage visit. Been driving for a couple weeks now without any issues. Should've gotten it sorted sooner, but hey, lesson learned! Really appreciate all the advice, helped me feel more confident about what needed fixing. Feels good to have it sorted properly!