BMW 8 Diesel Multiple Failures: Fuel Regulator Issue?

Hey there! I have some experience working on cars, and I actually faced almost identical symptoms on my 2017 BMW 6 Series diesel last year. I feel your pain! Those exact symptoms showed up on mine, the engine light, unstable performance, and that frustrating power loss. After diagnostic tests, it turned out my high pressure pump was failing. Had it fixed at my regular workshop, which took them about 2 days. Total bill came to around 1510 Euro, including parts and labor. Since then, my 6 Series has been running perfectly. Before I can give more specific advice, what's your mileage, and have you noticed any unusual fuel consumption lately? Also, has your engine been making any specific noises? These details would help me compare it better with what I experienced. I know BMWs well (had the 5 Series before this one), and these symptoms often point to fuel delivery issues, but let's get those details to be sure.

Thanks for sharing your experience! My BMW just hit 188876 KM, and I actually noticed higher fuel consumption for the past few weeks before these issues started. No strange noises yet, but the unstable idle is really concerning. Had my last service about 2 months ago, and everything was fine then. Your fuel pump theory might be spot on, the symptoms match up perfectly. I'll definitely get that checked out first. Did you notice any warning signs before your pump completely failed? Just wondering if I should drive it to the workshop or better get it towed to avoid any potential damage.

Hey again! Definitely good that you asked about the warning signs. Yeah, with my 6 Series, I actually did notice some subtle hints before things got really bad. About a month before the pump completely gave up, I started seeing slightly higher fuel consumption, just like you're experiencing now. In my case, I made the mistake of continuing to drive it for about a week after the symptoms started, and honestly, I wouldn't recommend doing that. The unstable idle got worse really quickly, and I ended up having to get it towed anyway. The mechanic later told me I could've caused more extensive damage to the fuel system by pushing it. Based on what happened with my car and seeing your symptoms are nearly identical to what I experienced, I'd strongly suggest getting it towed. The cost of a tow is way less than potentially damaging other components. When my pump failed, it started sending metal particles through the system, and I was lucky it didn't cause more damage. Tell you what, given your mileage is pretty close to what mine was when this happened (I was at about 175000 KM), and considering the similar symptoms, I'm even more convinced it's the same issue. Better safe than sorry with these high-pressure systems. Quick tip from my experience: make sure to keep the repair receipts and get a warranty on the new pump. Had to use mine when they needed to make some adjustments a week after the initial repair.

Thanks for that detailed explanation! You've convinced me, I'm definitely going to call for a tow rather than risk driving it. It's just not worth potentially causing more expensive damage to save a few bucks on towing. Makes total sense about the metal particles too, I hadn't even thought about that risk. The similar mileage on your car when it happened really helps confirm my suspicions. I'll get it booked in tomorrow morning and make sure to ask about warranty coverage on the parts. Really appreciate you taking the time to share your experience, it's given me a much clearer picture of what I'm likely dealing with and probably saved me from making things worse by continuing to drive it. I'll update once I get the diagnosis back from the workshop!