BMW X6 Knocking and Jerking: Engine Problems Decoded

Hey there! I have some experience working on BMWs and went through something very similar with my 2020 BMW X4 last year. The symptoms were nearly identical, rough running, jerking, and that annoying limp mode. After taking it to my trusted workshop, they found deposits built up in the combustion chamber causing those exact issues. Had to get the chamber cleaned and some related components checked. The whole thing cost me around 425 Euro, but it's been running smooth since then. I've also owned an X3 before, so I'm quite familiar with these engines. To help you better, could you share: What fuel grade are you using? When did these symptoms first appear? Have you noticed any warning lights? Did you scan for specific error codes? Let me know these details and I'll try to point you in the right direction before you head to the shop.

Thanks for the detailed response! Mine has 162563 KM on the clock and just had its service last month. I've been using premium fuel since day one, and the symptoms started about a week ago. The check engine light came on along with a glow plug indicator. Getting P0303 and P0316 codes from my scanner. Really appreciate the info about the combustion chamber deposits, that's super helpful and could definitely explain what I'm experiencing. It's good to know there might be a solution that won't break the bank completely. I'll get it checked out ASAP before it potentially causes any more damage.

Yeah those codes you mentioned (P0303 and P0316) definitely match what I experienced with my X4! The P0303 points to a cylinder 3 misfire, and P0316 suggests a misfire during startup, exactly what I dealt with. I should've mentioned in my first reply that my X4 had around 150000 KM when this happened, so pretty close to your mileage. The fact that you're using premium fuel is good, but sometimes these deposits can still build up even with the best fuel. My mechanic explained that it's just part of the normal wear and tear, especially in these direct injection engines. One thing I learned from my experience, don't wait too long to get it fixed. I initially tried to "drive through it" for a couple of weeks, but that only made things worse and could have caused more damage. The smoke you're seeing could be from incomplete combustion, just like what happened with mine. Since you mentioned having a service last month, might be worth checking with that workshop too. Sometimes these issues can be related to recent work done on the car, though in my case it was purely the carbon buildup. Let us know what you find out when you get it checked. I'm curious if it turns out to be the same issue as mine!

Thanks again for sharing your experience, it's really comforting to know I'm not alone in this! You're absolutely right about not waiting too long. After hearing about your experience, I've already booked it in for tomorrow morning at the workshop that did my recent service. The similarities between our cases are striking, especially the mileage and error codes. I was actually nervous about a major engine problem, but hearing that yours was solved with a chamber cleaning gives me hope it won't be as bad as I feared. I'll definitely follow up once I get the diagnosis. Really appreciate you taking the time to share all this detailed info, it's exactly what I needed to hear before taking it in. Knowing what to expect makes the whole situation way less stressful. Thanks again!