BMW XM Power Loss: Check Engine Signals Sensor Trouble

Hey there! I had similar symptoms with my 2020 BMW X6 M50i last winter. Check engine light, drop in power, and the car kept going into limp mode. Initially thought it was just a sensor, but turned out there was a crack in the exhaust manifold causing a leak. The garage found it during a pressure test of the exhaust system. The leak was allowing extra air in, messing with the sensor readings and causing the engine management system to go haywire. Had to get the manifold replaced along with some gaskets. It was a serious job that took a couple of days to fix. Since the repair, the car's been running perfectly, no more power issues or check engine lights. With your symptoms sounding so similar, I'd definitely get the exhaust system checked properly. These issues rarely fix themselves and can cause more damage if left untreated. The symptoms you're describing really do match what I experienced. Better to get it checked sooner rather than later.

Hey, glad you got yours sorted! That crack in the exhaust manifold sounds like exactly what I might be dealing with. Would you mind sharing roughly how much the whole repair set you back? Just trying to get an idea of what I might be looking at cost-wise. Also, curious if you've had any other issues pop up since the repair?

Hey again! Since you asked about the costs, I actually got lucky compared to your situation. My issue turned out to be just the faulty exhaust temperature sensor rather than a cracked manifold like I initially thought. The mechanic found a small leak in the exhaust system that they fixed along with replacing the sensor. Total bill came to 265 € which wasn't too bad considering what it could have been! Haven't had a single problem since the repair was done last month. The car's running like a dream now, no more check engine lights, power's back to normal, and fuel consumption is much better. The mechanic did a thorough job and even ran several tests afterward to make sure everything was working properly. Looking back, I was probably worrying too much when I wrote my first response, thinking it was something major like the manifold. Sometimes the simpler explanation is the right one! Let me know how you get on with yours, hopefully it's something straightforward like mine turned out to be.

Thanks for the update! You've actually given me some hope here. Just got back from a new mechanic I tried today, and guess what? It was indeed the exhaust temperature sensor! What are the odds? The repair was surprisingly quick, they diagnosed it within an hour and had it fixed the same day. Cost me about the same as yours. Such a relief it wasn't anything major like a cracked manifold. The mechanic was really thorough, explained everything clearly, and even showed me the faulty sensor. Car's running perfectly now, no more check engine light, power's back to normal, and fuel consumption has improved dramatically. Feels like I've got my BMW back! Really glad I didn't put off getting it checked. Sometimes these things turn out way simpler than we expect. Thanks again for sharing your experience, it really helped me make the decision to get it looked at sooner rather than later. Definitely learned my lesson about not waiting too long when these issues pop up!