BMW 4 Diesel: Injection System Troubles & Power Loss?

Hey there! I have some experience working on cars, and I actually faced something very similar with my 2013 BMW 3 Series diesel. Those symptoms sound really familiar, my 320d had the exact same issues. Turned out it was a faulty wiring connection to one of the injectors. Got it fixed at my workshop, they diagnosed it pretty quickly with their diagnostic equipment. The total repair came to 95 Euro, mainly for tracking down and fixing the damaged cable connection. After that, the car ran smooth as butter again. Have you noticed any warning lights on the dashboard? Also, does the jerking happen more when the engine is cold or warm? These details would help figure out if it's the same issue I had. For reference, I also owned a BMW 5 Series before this, so I'm quite familiar with how these engines should normally behave. Let me know those details, and I'll try to share more specific insights about what worked for me.

Thanks for sharing your experience! My car has 130202 KM and had its last service 3 months ago. The jerking definitely happens more when the engine is warm, and yeah, I've got the engine management light flickering occasionally. Your injector wiring issue sounds spot on, it would explain the poor fuel economy I'm seeing too. Did you notice any metallic clicking sounds before getting it fixed? I'm hearing that sometimes, especially during acceleration. Just trying to confirm if I'm dealing with the same problem before heading to the workshop. The symptoms match up pretty well with what you described. Thanks again for the help. It's reassuring to hear yours was a relatively simple fix!

Hey again! Yeah, those metallic clicking sounds are exactly what I experienced with my 3 Series too! Mine started around the 125,000 KM mark, and it was definitely that distinct clicking noise during acceleration that got me worried. It's almost like a ticking time bomb sound, right? Just to add to my previous response, after I got mine fixed, the mechanic showed me that the wiring insulation had worn away over time, causing intermittent connections to the injector. The clicking sound was actually the injector misfiring because of the poor electrical contact. That's why the engine management light was coming and going. One thing I didn't mention before, I initially tried ignoring it for about two weeks (big mistake), and the fuel consumption got dramatically worse. I was burning through about 20% more diesel than usual. After the fix, it went right back to normal. Since your mileage and symptoms are so similar to what I experienced, I'd really recommend getting it checked soon. The repair was pretty straightforward in my case, and it saved me from potentially bigger issues down the line. These diesel injectors can cause serious engine damage if left unchecked for too long. Keep us posted on what you find out at the workshop!

Thanks so much for the detailed follow-up! You've definitely convinced me to get it checked out ASAP. That 20% increase in fuel consumption you mentioned matches exactly what I'm experiencing, it's literally drinking diesel at this point! The clicking sound is exactly as you described, like a ticking time bomb, and it's getting more noticeable each day. I've actually just booked it in for tomorrow morning at my regular workshop. You're right about not waiting, I don't want to risk any serious engine damage. The fact that your repair was straightforward and relatively inexpensive is really encouraging. Will definitely update here once I get the diagnosis and repair done. Really appreciate you taking the time to share your experience in such detail, it's helped me understand what I might be dealing with and stopped me from putting off the repair any longer. Thanks again for all the help!