BMW 8 Diesel: DPF Issues and Emergency Mode Problems

Hey there! I had a similar issue with my 2018 BMW 7 Series diesel last year. I've got some experience working on cars, but with complex engine issues, I prefer leaving it to the pros. Your symptoms sound exactly like what I faced. Initially thought it was the sensor too, but turned out there was a leak in the exhaust system, which messed with the DPF readings and caused all those symptoms. Got it fixed at my regular workshop, cost me around 265 Euro. The mechanics found cracks in the exhaust manifold that were causing the problems. Since fixing it, my X7 has been running perfectly. Before I can give more specific advice, could you share: How many miles/kilometers on your 8 Series? When did these symptoms first appear? Any unusual sounds from the exhaust? Have you noticed any smoke from the exhaust? Once you share these details, I might be able to help further!

Thanks for your response! My car's at 66444 KM and just had its service last month. The symptoms started about a week ago. No unusual sounds from the exhaust, but I've noticed darker smoke than usual when accelerating. You mentioning the exhaust manifold is really helpful, I was so focused on the sensor that I hadn't considered that. Makes sense since it could explain all these issues happening at once. Guess I'll need to get it checked professionally to be sure. Did your car also have that significant power drop when the issue occurred? Just wondering if I should expect similar symptoms while driving it to the workshop.

Hey again! Yes, my car definitely had that noticeable power drop, it was running like it was in limp mode. Pretty much identical to what you're describing with yours. The darker smoke you're seeing is really similar to what I experienced too, especially during acceleration. At 66K km, you're actually at a similar mileage to when my issue occurred (I was around 70K). The power loss was really obvious when trying to accelerate on highways, felt like the car was holding back significantly. I managed to drive it to the workshop without any problems though, just had to be a bit gentler with the throttle. Thinking about your symptoms more now, especially that darker smoke, I'm even more convinced it could be similar to what I had. When they fixed my exhaust manifold, all these issues cleared up completely. The DPF started regenerating normally again, power came back, and fuel consumption went back to normal. Just keep an eye on the exhaust smoke and take it easy on the accelerator until you get it checked out. Better safe than sorry with these diesel engines. Let me know what your mechanic finds, would be interesting to see if it's the same issue!

Thanks so much for all the detailed info! It's really reassuring to hear from someone who's dealt with such a similar situation. I'll definitely drive carefully to the workshop tomorrow, good to know you managed to get there without issues despite the power loss. Your experience is super helpful, especially about the exhaust manifold repair fixing all those problems at once. Crossing my fingers it's the same issue, would explain everything from the DPF problems to the dark smoke. I'll follow your advice and take it easy on the acceleration. I'll update you once I get it checked out. Really appreciate you taking the time to share your experience, definitely feeling more confident about getting this sorted now! Thanks again for walking me through what to expect.