BMW X3 Rough Idle & Vibration Mystery: Owner Seeks Help

Hey! Had similar issues with my 2013 BMW X5 last winter. Those symptoms definitely rang a bell, my car had the same rough running and vibrations. Initially thought it was the engine mount too, but turned out it was just a faulty connector to one of the ignition coils that was loose and corroded. Took it to my regular workshop, they ran diagnostics and traced it to a bad cable connection. Fixed it up for about 95 Euro, mainly labor costs since they had to clean the connections and replace a damaged plug. Car's been running smooth since then. Before I can help more specifically, what engine variant is your X3 running? And have you noticed if the vibration gets worse at specific RPMs? The 3-series and X-series from that era had some common issues, but knowing the exact specs would help narrow things down. Really sounds like what I experienced, but best to confirm the details first. Let me know!

Thanks for sharing your experience! I've got the 2.8i gasoline variant with 178382 KM on the clock. Actually, now that you mention it, the vibration does get more noticeable around 1500-2000 RPM, especially when I'm idling at traffic lights. Was your connector issue throwing any specific error codes? Just had my service done last month and everything else seemed fine, so I'm hoping it's something similarly straightforward like in your case and not a major engine mount issue. Fingers crossed it's just a connection problem!

Hey again! Yes, looking at your symptoms and especially now knowing it's the 2.8i, it sounds even more similar to what I dealt with. My X5 also showed the worst vibrations in that exact RPM range. The error code I got was related to cylinder misfiring, can't remember the exact code but it was something pointing to the ignition system. Since you mentioned having similar vibration patterns at those specific RPMs, I'm pretty convinced you might be dealing with the same connector/coil issue. One thing I forgot to mention in my first reply, before taking it to the workshop, I actually noticed the vibrations were a bit less severe on warm days. That was another clue pointing to the electrical connection problem rather than a mechanical engine mount issue. Given that your car's mileage is pretty close to what mine was when this happened (mine was around 165000 KM), these electrical gremlins start showing up. The good news is that if it is the same issue, it's way cheaper to fix than an engine mount replacement. Maybe try this, next time it acts up, pay attention if the vibration changes with temperature. If you want, I can tell you what the workshop did exactly to diagnose it in my case.

Thanks, that's super helpful info! You're giving me hope it's not going to be an expensive fix. Actually, now that you mention the temperature thing, I've noticed the car does run a bit smoother in the afternoon compared to my morning commute. That does sound more like an electrical issue than mechanical. Would definitely appreciate knowing what diagnostic steps your workshop took. I've got an appointment scheduled for next week, and it would be great to go in there with some specific things to ask them to check. My error code is P0301, which from what I've read does point to cylinder misfiring like you mentioned. Really appreciate you taking the time to share your experience, might've just saved me from unnecessarily replacing an engine mount!