BMW X4 DPF Failure Signs: Black Smoke and Power Loss

Had the exact same symptoms on my BMW X3 2018 diesel last winter. Black smoke and power loss were the main red flags, along with that annoying warning light. Turned out the exhaust back pressure sensor was failing, causing incorrect DPF regeneration cycles. Took it to the shop, and they confirmed my suspicion after running diagnostics. The sensor needed replacement, and they also cleaned the DPF since it had accumulated excess soot due to the faulty sensor. It wasn't a hugely complex repair, but ignoring it could've led to complete DPF failure, which would've been much more serious. Your symptoms match what I experienced pretty closely. The black smoke and power loss are classic signs of DPF problems. Get it checked soon, better to handle it now than risk bigger issues. Mine's been running smoothly since the fix, no problems with regen cycles or performance.

Thanks for sharing your experience! That sounds exactly like what I'm dealing with right now. It's really helpful to know what it turned out to be in your case. How much did you end up paying for the sensor replacement and DPF cleaning? Also, have you had any other issues pop up since getting it fixed?

Hey there! Glad I could help, and yes, I can update you on everything. Just got the car back from the mechanic last week, and they confirmed it was indeed the exhaust back pressure sensor playing up, exactly what I had suspected. Total bill came to 245 € for replacing the sensor, which honestly wasn't as bad as I was fearing. The best part? No more DPF warning lights or issues since the fix! The car's running like a dream now, no more black smoke, full power restored, and the exhaust pressure readings are spot on. It's such a relief when you get these things sorted properly. No other problems have shown up since the repair, and trust me, I've been watching it like a hawk! The engine feels much smoother during acceleration, and those nasty exhaust smells are completely gone. If you're experiencing similar symptoms, I'd definitely recommend getting that sensor checked out. It's way cheaper to fix this early than to end up with a completely clogged DPF. Let me know if you need any other details about what they did during the repair. Happy to share more info!

Thanks for all that detailed info! I actually just got back from the mechanic yesterday, and you were spot on. It was the same issue, faulty exhaust back pressure sensor. What a relief it wasn't something more serious! My repair came in around the same price range as yours. The mechanic was really thorough and even showed me the readings before and after the fix. Already noticing a huge difference, no more black smoke, and the engine's got its pep back. Really appreciate you taking the time to share your experience. Helped me feel more confident about getting it sorted quickly instead of waiting around. Cars running smooth now, and hopefully that's the last I'll see of those warning lights for a while! Thanks again for all your help with this. It's great when these things turn out to be straightforward fixes rather than major headaches.