BMW X5 Rough Running: MAF Sensor or Something Else?

Hey there! I had a similar issue with my 2006 BMW X3 last year (I have some experience working on cars, mostly basic maintenance). Those symptoms sound exactly like what I went through, rough running, jerking, and terrible fuel economy. My check engine light was also on. Initially tried cleaning the MAF sensor myself, but that didn't help. Took it to my regular workshop and they confirmed it was a faulty MAF sensor. Total replacement cost me 365 Euro, but the car's been running like new since then. The difference in performance was night and day. Before I can share more specific details, could you tell me if you've had any other warning lights or noticed any unusual sounds? Also, have you scanned for error codes? These details would help confirm if you're dealing with the same issue I had. Most BMW models from that era had similar MAF sensor setups, so the fix should be straightforward for a good mechanic.

Thanks for sharing your experience! My X5 is at 123358 KM and just had its service last month. I've got the check engine codes scanned, getting P0171 and P0174, which point to a lean condition. No other warning lights or strange sounds, just the symptoms I mentioned. Good to hear replacing your MAF sensor fixed similar issues. Did you notice any immediate improvement in fuel consumption after the replacement? Mine's been drinking fuel like crazy lately, and I'm hoping it's just the MAF sensor and not something more serious. My mechanic quoted roughly the same price range for the replacement. Did you go with OEM or aftermarket parts for your repair?

Hey again! Yes, I definitely noticed an immediate improvement in fuel consumption after replacing my MAF sensor! It was like getting a new car. My X3 went from guzzling fuel like crazy back to its normal consumption, saved me quite a bit at the pump. Those codes you're getting (P0171 and P0174) are exactly what I had. They're classic signs of a bad MAF sensor in these BMWs. Since your mileage is pretty close to what mine was when it failed (mine was around 135000 KM), it makes even more sense. I went with an OEM Bosch sensor, didn't want to risk any compatibility issues with aftermarket parts. Sure, it was a bit pricier, but totally worth it. The mechanic told me aftermarket sensors can be hit or miss with these cars, and I didn't want to end up replacing it twice. Just a heads up, after the replacement, it took my car about 50-60 KM to fully adjust to the new sensor. The ECU needed to relearn some parameters, but after that, everything was perfect. No more jerking, stalling, or rough idle. The engine light cleared up right away too. Trust me, you're making the right call getting it checked out. Better to fix it now than risk any long-term damage to the engine from running lean.

Thanks so much for all the detailed info! Really helpful to hear about your experience, especially about going with the OEM Bosch sensor. I'll definitely take your advice and avoid aftermarket parts, don't want to deal with compatibility issues or having to do the job twice. Good to know about the adjustment period too. I'll keep that in mind and won't panic if it's not perfect right after the replacement. I've already booked my car in for next week, and your experience has made me feel much more confident about the repair. The symptoms match exactly, and the fact that your fuel consumption went back to normal after the fix is really encouraging. I'll probably go ahead with the OEM sensor replacement, and fingers crossed it sorts out all these issues just like it did for your X3. Thanks again for taking the time to share your experience, it's been super helpful!