BMW Diesel DPF Issues, Temp Sensor or Something Worse?

Hey there! I have some experience working on cars, and I actually dealt with a similar issue on my 2012 BMW 3 Series Diesel (had a 1 Series before that). The symptoms you're describing sound exactly like what I experienced. After struggling with it for a bit, I took it to my regular workshop where they found a leak in the exhaust system, right before the DPF. That was causing incorrect readings and messing with the whole system. The fix took about 4-5 hours, and I ended up paying 265 Euro for parts and labor. Since then, everything's been running smoothly, no more limp mode, normal fuel consumption, and DPF regen working properly. Could you share more details about your car, like the exact model and mileage? Also, are you getting any specific error codes? This would help me give you more targeted advice since these symptoms can sometimes point to different issues depending on the specific model.

Thanks for sharing your experience! I've got the same BMW 2 (97206 KM on the clock, just had a service last month), and your situation sounds very similar to what I'm dealing with. The exhaust leak theory makes a lot of sense actually, that price sounds much better than what I was worrying about paying for a complete sensor replacement. Did you notice any unusual exhaust sounds before finding the leak? I'm trying to figure out if I should look out for that too. Your solution gives me hope it might be something relatively straightforward rather than a major DPF issue.

Hey again! Yeah, looking back at your mileage, it's pretty similar to when I had my issue (mine was around 95k). And you know what's interesting? Before they found the leak, I was also convinced it was just a sensor problem. About the exhaust sounds, actually, I did notice a slight whistling noise when accelerating, but it was so subtle I initially thought I was just being paranoid. It wasn't until after the repair that I realized how much quieter the car had become. Keep an ear out for that, but honestly, it might not be obvious in all cases. What really made me think of an exhaust leak in your case is how similar your symptoms are to what I experienced, especially that combination of limp mode and DPF regen issues. The fact that your car just had a service is interesting too, sometimes these problems can show up shortly after work's been done on the car if something wasn't sealed properly. I'd suggest having your mechanic do a proper pressure test on the exhaust system. That's how they found my leak, it wasn't even visible to the naked eye. Just make sure they check the whole system, especially around the DPF connections. The money I spent on diagnosis was worth every penny because it saved me from unnecessarily replacing parts. Let me know what you find out, I'm curious to see if we had the same root cause!

Thanks so much for all that detailed info! That whistling sound you mentioned, now that you say it, I have been hearing something similar but kept brushing it off. I'll definitely get that pressure test done. Really appreciate you taking the time to explain everything, especially about the post-service timing, that's got me thinking since these issues did start pretty soon after my last service. I've already called my mechanic and booked it in for tomorrow morning. They're going to do the pressure test first before jumping to any conclusions about sensors. I'll let you know what they find, but I've got a feeling you might be spot on with the exhaust leak theory. Thanks again for saving me from potentially unnecessary parts replacement!