BMW X4 Running Rough, Limp Mode & Multiple Engine Issues

Hey there! I have some experience working on BMWs, and this reminds me of an issue I had with my 2015 BMW X3. Had very similar symptoms to what you're describing. Turned out to be a leak in the exhaust system that was messing with the oxygen sensors. Took it to my regular workshop, and they found a crack near the manifold that was causing all sorts of havoc. Cost me around 265 Euro to get it all sorted. Before I give you more specific advice, could you tell me if you're getting any specific error codes? Also, have you noticed any unusual exhaust sounds or smells? The X4 and X3 share a lot of components, so I might be able to help if I know more details. The fix really sorted out all those symptoms, no more check engine light, smooth acceleration, and passed emissions with flying colors. Let me know those details, and I can share more about what worked for me.

Thanks for sharing your experience! My X4 just hit 122040 KM and had its last service about 3 months ago. I am getting error code P0301, which points to cylinder 1 misfire. Haven't noticed any weird exhaust smells, but there's definitely a slight rattling noise when idling. The jerking seems worse when the engine is cold, if that helps narrow things down. Did your repair shop mention anything about checking the ignition coils or spark plugs when they found that exhaust leak? Just trying to figure out if I should expect something similar or if I'm dealing with a different beast altogether.

Hey again! Thanks for those details about your X4. Interesting, when you mentioned the P0301 code and the cold start issues, it's actually quite different from what I dealt with on my X3. While my problem was that exhaust leak, yours is definitely pointing towards the ignition system, which makes sense with that cylinder 1 misfire code. Actually, after you mentioned it, I recalled that about a year before my exhaust issue, I had somewhat similar symptoms, the rough idle and jerking during cold starts. Turned out my ignition coils were shot, and one of the spark plugs was pretty worn too. The mechanic replaced all four coils and plugs just to be safe (cost about 400 Euro total), and it fixed those exact symptoms you're describing. The rattling noise you're hearing is pretty typical for a misfire situation, had the same thing. I'd bet money that you're looking at either bad coils or plugs, especially given your mileage. Mine started acting up around 115000 KM, so the timing tracks. If you want my advice, I'd get those coils and plugs checked first before diving into anything more complex. It's usually the simpler fix, and it's way more common than my weird exhaust leak situation. Let me know what you find out, really curious if it turns out to be the same issue!

Thanks so much for the detailed response! That's really helpful, especially knowing about your experience with both the exhaust and ignition system issues. You've actually made me feel a lot better about this, I was worried it might be something catastrophically expensive, but coils and plugs sound much more manageable. I've just booked it in at my mechanic for tomorrow morning, and I'll definitely have them check the ignition system first. The fact that your car had similar symptoms around the same mileage really helps confirm my suspicions. The price you mentioned for the coils and plugs replacement sounds reasonable too, definitely better than what I was imagining! I'll give you an update once I get the diagnosis. Really appreciate you taking the time to share your experiences. It's always reassuring to hear from someone who's dealt with similar issues, especially with these BMWs that can be a bit tricky sometimes!

My BMW 5 series 2008 has a rough idle and jerking throttle response until it gets warm. Any ideas on how to get rid of this problem

Start by checking the condition of your spark plugs and ignition coils, as these are common culprits for rough idling and jerking, especially when the engine is cold. If they are worn or faulty, replacing them could resolve the issue. Let me know if this helps or if you have any further questions!