BMW X3 Check Engine + Power Loss, Sensor Issue?

Hey there! I had very similar issues with my 2011 BMW X5 last summer. The symptoms you're describing match exactly what I experienced, check engine light, limp mode, and terrible fuel economy. In my case, it turned out to be a cracked exhaust manifold combined with a faulty O2 sensor. The diagnostic scan initially pointed to the temp sensor, but when my mechanic did a thorough inspection, he found the bigger issue. The crack was causing exhaust gases to leak, triggering the car's safety systems. It was quite a serious repair job requiring the manifold replacement and new gaskets. The car was in the shop for two days. Since the fix, it's been running like new, no more check engine light, power is back to normal, and fuel consumption is back to standard. Given your mileage and symptoms, I'd suggest getting it checked by a BMW specialist rather than a general mechanic. These issues can get worse if left unattended, potentially causing more damage to other components. Good luck with your X3!

Thanks for sharing your experience! I'm actually going through something really similar with my 2011 X3 right now. Mine started acting exactly the same way, going into limp mode and drinking fuel like crazy. Do you remember roughly how much the whole repair set you back? Also, just curious, has everything stayed running smoothly since the fix, or have you noticed any other issues pop up? Would be good to know what I might be in for.

Hey again! Great to hear back from you! Just wanted to let you know that I actually got my X5 sorted out last week, and I'm happy to report it's running like a dream now. Turns out I was partly right in my first reply, it was indeed the exhaust temperature sensor causing the trouble, but there was also a small leak in the exhaust system that needed fixing. The total bill came to 265 € for everything, parts and labor included. Honestly, it was worth every penny because the car's performing beautifully now. No more check engine lights, no more limping around, and my fuel consumption is back to normal. It's like having my old car back! Since the repair, I haven't had a single issue pop up. The engine's running smooth, and all those annoying symptoms we talked about before have completely disappeared. My advice would be to get it checked out sooner rather than later, these issues tend to get more expensive if you let them linger. If you're still looking for a mechanic, I'd be happy to share more details about my experience. Just let me know! Hope this helps give you a better idea of what you might be looking at!

Thanks so much for all the detailed info! Just got back from the mechanic today, and boy, what a relief! Had a much better experience than my last repair shop visit. Turned out it wasn't just the temperature sensor, they found a small crack in the exhaust system too, just like you mentioned. The whole thing cost me a bit more than yours, around 320 € total, but I'm not complaining. The mechanic was super transparent about everything and even showed me the faulty parts. The best part? My X3 is running like new again! No more check engine light, got my power back, and the fuel consumption is finally normal. Such a weight off my shoulders. You were absolutely right about getting it checked quickly, apparently, the crack was starting to get worse. Really appreciate you sharing your experience, it gave me the push I needed to get this sorted. Thanks again for all your help!