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TobiMai

BMW 4 DPF Nightmare: Smoke, Power Loss & Failed Tests

Black smoke from exhaust on acceleration

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Loss of engine power

Hi everyone. My 2018 BMW 4 diesel is acting up lately. Getting DPF warning lights, reduced power and lots of smoke under acceleration. Car's also failing emissions and showing multiple DPF-related error codes. Pretty sure the diesel particulate filter is the culprit. Has anyone dealt with similar symptoms? Interested to know what the repair process was like and what kind of solutions your workshop came up with. Any tips or experiences would be great.

4 comment(s)


MattKohlRider

Hey there! I have some experience with cars and went through something very similar with my 2016 BMW 3 Series diesel. Also own a BMW 5 Series, so I'm quite familiar with these issues. Had the exact same symptoms, DPF warnings, power loss, and that annoying smoke. My mechanic confirmed it was a failed DPF after running diagnostics. Got it replaced and the whole thing cost me around 1550 Euro, but it solved all the problems completely. The repair took about a day and a half at my trusted workshop. Since then, I've had zero issues with emissions or performance. What's your mileage and maintenance history? Also, has your car been used mostly for short trips? These details would help me understand if your situation matches what I experienced. Would love to share more specific insights based on your case.

TobiMai (Author)

Thanks for sharing your experience! Yeah, my car's at 126054 KM and had its last service about 3 months ago. Really helpful to know about your repair costs and timeline, gives me a better idea of what I'm looking at. Good to hear it sorted out all your issues completely. I do mostly highway driving, so it's strange that I'm having DPF problems. Think I'll get it checked by my mechanic soon before it gets worse. Thanks again for the advice!

MattKohlRider

No worries at all! Since we're talking about similar BMW diesels, I can totally relate. Highway driving usually helps prevent DPF issues, which makes your case quite interesting. My 3 Series had about 135000 KM when the DPF failed, so we're in the same ballpark mileage-wise. Just a heads up based on my experience, even with mostly highway driving, these filters can still get clogged if the regeneration cycles aren't completing properly. After my repair, my mechanic mentioned that sometimes the DPF sensor can be the culprit too, giving false readings. Might be worth having them check that as well. I got lucky because I caught it early. The repair was expensive, but it would've been worse if I'd kept driving with the warning lights on. Since you're already getting smoke and power loss, definitely get it looked at soon. The emissions test failure is exactly what happened to me right before I got it fixed. If you want, I can share the maintenance schedule I've been following since the repair, it's helped keep my DPF healthy for the past couple of years. Let me know if that would be useful!

TobiMai (Author)

Thanks so much for all this detailed info! Really appreciate you taking the time to explain everything. It's good to know about the possibility of sensor issues too, I'll definitely have them check that when I take it in. You're right about catching it early, and those warning signs are pretty clear now that I think about it. Would love to see that maintenance schedule you mentioned, anything that helps prevent this from happening again would be super helpful! I'll go ahead and book it in with my mechanic tomorrow. Actually feeling much better about the whole situation now that I know what to expect. Thanks again for sharing your experience, it's been really helpful!

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