BMW X6 Power Loss: Fuel Regulator or Something Else?

Had exactly the same symptoms on my 2015 BMW X5 35i last summer. Turned out to be a failing high-pressure fuel pump. Started with rough idle, then drop in power, and finally got the engine light. The car would sometimes stall at traffic stops, which was really concerning. After diagnosis, they confirmed the high-pressure pump was defective. It's actually a common issue on these N55 engines. The repair involved replacing the entire pump unit, not something you can patch up. This was definitely a serious repair that needed immediate attention since it affects the entire fuel delivery system. The car runs perfectly now, no more stalling or power loss issues. If your symptoms match mine, I'd strongly suggest getting it checked by a certified BMW mechanic specifically for the high-pressure pump. The longer you wait, the more risk you're taking with potential engine damage.

Thanks so much for sharing this! I'm relieved to hear I'm not the only one who faced this. My symptoms sound identical to what you experienced with your X5. Quick question, do you remember roughly how much you ended up paying for the fuel pump replacement? Also, has everything been running smoothly since the repair, or have you noticed any other issues pop up? I'm planning to take it to a specialist this week, but it helps to know what I might be looking at cost-wise. Thanks again for the detailed explanation!

Hey there! Glad I could help with the info earlier. Yeah, I just got my X5 back from the shop last week actually. You were spot on about the symptoms being identical, and turns out it was indeed both the fuel volume regulator and that pesky high-pressure pump giving me grief. The damage came to 1510 € for the high-pressure pump replacement, which wasn't exactly easy on the wallet, but honestly, it was worth every penny. Since getting it fixed, it's running like a dream, smooth as silk with no more of that annoying stalling or power loss. The fuel volume regulator issue got sorted too, which was a bonus. I can't tell you what a relief it is to not have that anxiety every time I stop at a light, wondering if the car's going to stall! If you're heading to the specialist this week, you're definitely making the right call. These BMWs really need someone who knows what they're doing, especially with fuel system issues. Keep us posted on how it goes with your X6. Always good to hear how these things turn out!

Thanks for the follow-up! Just got back from the mechanic today and wanted to update you. You were absolutely right about everything. The specialist confirmed it was the high-pressure fuel pump causing all the trouble. They also spotted a worn-out fuel volume regulator, just like in your case. The total bill came to about 1600 € for everything, including labor. A bit more than I hoped for, but after driving it home, I can tell it was money well spent. The engine runs beautifully now, no more rough idling, no stalling, and the power delivery is back to normal. It feels like a completely different car! Really appreciate you sharing your experience. It helped me feel more confident about getting it fixed instead of putting it off any longer. Funny how similar our situations were! I'll definitely be keeping up with the maintenance from now on. Thanks again for all your help!