BMW X6 Jerking & Limp Mode Issues, Diagnosis Help

Hey there! I have some experience working on BMWs, having dealt with a similar issue on my 2021 BMW X4 last year. Sounds familiar, my car showed the same symptoms. Had to take it to my trusted mechanic who found a leak in the exhaust system near the manifold. Ended up costing me 265 Euro for parts and labor, but it fixed the rough running and limp mode completely. The leak was causing incorrect readings in the oxygen sensors, which confused the ECU. Before suggesting anything specific though, could you share: Current mileage? Any unusual sounds/smells? Did this start suddenly or gradually? The X6 and X4 share quite a bit mechanically, so I might be able to help more with those details. Had a good experience with my mechanic and can share more specifics about the repair process if it seems similar to your case.

Thanks for sharing your experience! My X6 has 24010 KM on the clock and just had its latest service. Actually, no unusual smells but I've noticed a slight rattling noise on cold starts. The issue started gradually over the past couple weeks before going into limp mode. Your exhaust leak situation is interesting, I've been noticing slightly higher fuel consumption lately which could be related. Did your mechanic mention any other potential causes to look out for? Want to gather as much info as possible before taking it in.

Hey again! Since you mentioned the higher fuel consumption, that's exactly what I noticed with my X4 before things got worse. The rattling noise on cold starts is also really familiar, mine did the same thing. When I took it to my mechanic, he actually mentioned a few other potential causes he checked before finding the exhaust leak. There could be issues with the ignition coils or spark plugs, these were the first things he tested on my car. Also, given your mileage is similar to what mine was when I had the problem (I was at about 25000 KM), it might be worth checking the O2 sensors too. I learned the hard way that these symptoms can cascade pretty quickly. Within about three weeks of noticing the initial fuel consumption increase, my car went into full limp mode. The repair itself wasn't too complex once they found the actual issue, but the diagnosis took a bit of time because these symptoms can point to multiple problems. Just keep in mind, even though the latest service was done recently, these issues can develop pretty quickly. My advice would be to get it checked soon before it potentially gets worse like mine did. The repair cost might vary depending on what they find, but it's worth fixing before it affects other components.

Thanks so much for the detailed response! That's really helpful to know about the ignition coils and O2 sensors too. You're right about not waiting, I've already called my dealer and booked it in for tomorrow morning. Better safe than sorry, especially since the symptoms match your experience so closely. The limp mode is already frustrating enough, definitely don't want to risk more issues developing. I'll update you once they diagnose it, would be interesting to see if it turns out to be the same exhaust leak problem. The cold start rattle combined with the fuel consumption really makes me think you might be onto something there. Really appreciate you taking the time to share your experience and all the potential causes. At least now I can have an informed conversation with the mechanic about what to check first!