BMW 8 Diesel: Multiple Problems Point to Boost Issues

Hey! I have some experience working on cars, and I actually dealt with something very similar on my 2019 BMW 7 Series diesel. The symptoms you're describing sound exactly like what I experienced. After the same issues (power loss, weird noises, and that annoying check engine light), I took it to my workshop. Turned out to be a faulty wastegate valve, it was stuck partially open, causing all those boost pressure problems. The repair set me back about 860 Euro, but it solved everything completely. My mechanic explained that it's actually not uncommon on these engines. Before suggesting anything specific though, could you share: Current mileage on your car? When did these symptoms first appear? Have you noticed any black smoke from the exhaust? This would help me give you more relevant advice based on my experience with the X6 (my owns one) and other BMW diesels I've dealt with.

Thanks for the detailed response! Just had my last service about 2,000 KM ago at 139,881 KM. Actually, I have noticed some black smoke recently, especially when accelerating hard. The symptoms started about three weeks ago, getting gradually worse. The wastegate issue you mentioned makes a lot of sense given what I'm experiencing. Good to know there's a potential fix, even though that repair cost isn't exactly pocket change! Did you notice any warning signs before it completely failed? Also wondering if you tried any diagnostic steps before heading to the workshop? Just trying to be better informed before I take it in.

Hey again! Thanks for those extra details about your BMW 8. You know, the black smoke you mentioned is exactly what I saw with my 7 Series before things got worse. Before my wastegate completely failed, I actually ignored some early warning signs, mainly that subtle whistle noise that got louder over time. Started really small, like barely noticeable, then got more obvious during acceleration. Looking back, I should've acted sooner because waiting just made the fuel consumption worse. Before taking it to the workshop, I tried using an OBD scanner to read the error codes, got P0299 and P2263, which pointed to the boost system issues. But honestly, that just confirmed what I already suspected from the symptoms. One thing I learned from my experience, don't try to drive it too long with these symptoms. I pushed mine for about a month, and the poor performance and extra fuel costs probably ended up costing me more than if I'd just fixed it right away. Sounds like you're dealing with pretty much identical issues to what I had. Given your mileage and the symptoms, especially that black smoke, I'd bet good money it's the same wastegate problem. Feel free to ask anything else about my repair experience, happy to share more details!

Thanks so much for all this helpful info! Those OBD codes you mentioned are definitely worth checking, I've got a basic scanner in my garage, so I'll run that first thing tomorrow. Really appreciate you sharing those early warning signs too. Honestly, I've probably been making the same mistake you did by driving it longer than I should have. The whistling noise has definitely gotten more noticeable in the past week, and my fuel costs are through the roof. Think I'll stop being stubborn about it and book it in for repairs next week. Rather pay for the fix now than keep burning extra fuel and risk more damage. Really helpful to hear from someone who's been through the exact same thing. You've saved me a lot of guesswork and probably some cash too by helping me narrow down the problem. Thanks again for taking the time to share your experience!

Hello, on my BMW 1 Series (model year 2011), 1.6L petrol engine with 136 hp, the error message appears from a speed of over 130 km/h: 'Drive - continued driving possible'. However, the power is not reduced. When reading out the error memory, the following error code was displayed: 120308 - boost pressure control, plausibility: pressure too low. Could you help me?" Regards Ramouk

(Translated from German)

Start by checking for any visible leaks or loose connections in the intake and turbocharger system, as these can cause low boost pressure. If everything looks secure, inspect the turbocharger hoses and intercooler for any signs of damage or wear. Let me know how it goes or if you have any further questions!