BMW 4 Diesel: Stalling Issues & Power Loss Mystery

Hey there! I've got some experience working on cars (not a pro, but I've dealt with my share of issues). Had a similar problem with my 2018 BMW 3 Series diesel last year. The symptoms you're describing sound exactly like what I went through, engine light, rough idle, drop in power, the works. Initially thought it was something minor, but turned out my high-pressure fuel pump was failing. Had it checked at my workshop, they diagnosed it pretty quickly (about an hour) because these symptoms are quite typical for this issue. The repair set me back about 1510 Euro, including parts and labor. They had to replace the entire pump unit. Before I can give you more specific advice, can you share if you're getting any specific error codes? Also, when was the last time you changed your fuel filter? These details would help determine if you're facing the same issue. If it's the same problem, don't wait too long to get it checked. These symptoms usually get worse and could potentially cause more damage. On a side note, I've heard similar stories from other BMW 4 and 5 Series owners, so it's not uncommon in these models.

Thanks for the detailed response! Just had my service done at 104915 KM and everything was fine then. The error code I'm getting is P0087, which seems to match your fuel pump theory. Started small but got worse over the last week. Will definitely get it checked out asap. Been using good quality diesel and changing filters regularly, so pretty surprised by this. Any chance you remember how long the repair took once they had the parts?

Hey again! Yeah, that P0087 code definitely rings a bell, it's exactly what I got with my fuel pump issue. The error code pretty much confirmed what we suspected. In my case, once they had the parts in hand, the actual repair took about 5-6 hours. They had to drain the fuel system, replace the pump, and then prime everything properly. My mechanic wanted to be thorough and did some additional testing to make sure everything was working correctly after the replacement. You're actually in a better position than I was, you caught it earlier. I stupidly drove around with the symptoms for about three weeks before getting it checked (not my brightest moment). The fact that you're maintaining it well with quality fuel and regular filter changes is good, but sometimes these parts just fail. It's one of those things that can happen regardless of how well you take care of the car. One tip though, when you get it fixed, make sure they check the fuel lines too. In my case, they found some debris in the lines from the failing pump, so they had to flush the system thoroughly. Might be worth asking about that when you take it in. Let me know how it goes when you get it sorted. Always curious to hear if others have the same experience I did with these BMWs!

Thanks so much, that's super helpful information! It's actually a relief to hear your experience matches mine so closely. I'll definitely mention the fuel line check when I take it in, wouldn't want any debris causing problems later. Called my workshop and they can take it first thing tomorrow morning. Five to six hours for the repair doesn't sound too bad, though I'll have to figure out how to juggle my schedule around it. Really appreciate you taking the time to share all the details about your repair experience. Will try to remember to update you once it's fixed. Good looking out with those maintenance tips too!