BMW X6: Rough Idle and Sluggish Performance Issues

Hey there! I had a pretty similar issue with my 2019 BMW X5 last year (I have some experience working on BMWs, but mostly basic maintenance stuff). The symptoms you're describing sound exactly like what I went through. After taking it to my regular workshop, they diagnosed it as a loose connection in the knock sensor wiring harness. The plug had partially disconnected, causing those exact symptoms, rough idle, poor performance, and that annoying check engine light. Total repair cost was 95 Euro, mainly for diagnostic time and fixing the connection. Just to help you better, what engine variant does your X6 have? Have you noticed any other symptoms, like misfiring or unusual noises? This info would help determine if you're dealing with the same issue I had.

Thanks for sharing your experience! I've got the gasoline variant and I'm dealing with exactly those symptoms you mentioned. No unusual noises, but definitely feeling that sluggish response. Just had my service at 145786 KM, and everything was fine until last week. Interesting that you mention the knock sensor wiring, I was hoping it wouldn't be anything major. Did your BMW throw any specific error codes when you got it checked? Your repair cost seems reasonable, gives me hope it won't break the bank!

Hey again! Yes, my X5 did throw some specific error codes, P0325 and P0332, which are typically associated with knock sensor circuit issues. When I took it in, they hooked it up to their diagnostic tool and these codes popped right up. Just to add to what I mentioned before, after they fixed that loose connection, my car went back to running like new. The improvement in performance was immediate. The throttle response became crisp again, and my fuel economy went back to normal within the next tank of fuel. Since you've mentioned your car was fine after the recent service, I'd bet you're dealing with something similar to what I experienced. The wiring connections can work themselves loose over time, especially with all the engine vibration. I'd suggest getting it checked soon though, running with a faulty knock sensor signal can potentially cause the engine to run rich to protect itself, which explains your fuel consumption issues. Quick tip, while you're waiting to get it checked, try driving a bit more gently. When my X5 was acting up, I noticed it responded better when I wasn't pushing it too hard. Let me know how it turns out, I'm curious if it's the same issue I had!

Thanks so much for all that detailed info! Those error codes definitely help narrow things down. I actually just scheduled an appointment for tomorrow morning to get it checked out. You've made me feel a lot better about this whole situation, I was worried it might be something major with the engine itself. I've been taking it easy with the driving like you suggested, and you're right, it does seem to behave better when I'm gentle with it. The fact that your repair was straightforward and fixed all the issues is really encouraging. I'll definitely update you once I get the diagnosis. Really appreciate you taking the time to share your experience, especially all those specific details about the codes and symptoms. Fingers crossed it's just that loose connection!