BMW 1 Series Power Loss: Help Diagnose Engine Jerking

Hey there! I've got some experience with BMWs and had a very similar issue with my 2009 BMW 3 series (also owned a 5 series before). Your symptoms sound exactly like what I dealt with. Mine started jerking and losing power out of nowhere, especially during acceleration. Took it to my trusted workshop and turns out it was caused by a dodgy chip tuning job done by a previous owner. The ECU was basically fighting with the tuning software. Cost me about 180 Euro to get it sorted, they had to reset the ECU to factory settings and clean up all the messy coding. Could you share more details about your car? Like if you've had any recent modifications or tuning work done? Also, what's the exact fault code you're getting? This would help pinpoint if we're dealing with the same issue.

Thanks for sharing that experience! My 1 series has 180047 KM on the clock and just had its service last month. I've never done any tuning or mods, kept it completely stock. The fault code I'm getting is P0101, but what's weird is that the jerking doesn't happen all the time. Sometimes it runs perfectly fine for days, then suddenly starts acting up again. Wondering if it could be something simpler like a dirty sensor or fuel injector issue rather than ECU problems?

Hey again! Ah, that P0101 code definitely rings a bell, it's different from what I had with my 3 series. With that mileage and the intermittent nature of the problem, I'm actually thinking it's likely your Mass Air Flow (MAF) sensor. Had a with the same symptoms in his 3 series, and it turned out to be exactly that. The intermittent behavior is super typical of a failing MAF sensor. These sensors get dirty over time and start sending wonky readings to the ECU, which then gets confused about how much fuel to inject, hence the jerking and power loss. In my case, it was the chip tune causing havoc, but since yours is stock, I'd bet money on the MAF sensor. It's actually a pretty common issue on these engines. The good news is that it's way cheaper to fix than my ECU drama. You might even get away with just cleaning the sensor first, sometimes that's all it needs. Tell you what though, before you take it to the workshop, try disconnecting your battery for about 15 minutes. This resets some adaptive values and might temporarily improve things. If it runs better for a short while after that, it's another sign pointing to the MAF sensor. Would love to hear what your workshop says when you get it checked out!

Thanks so much for all that detailed info! Just got back from the workshop and you were spot on, it was indeed the MAF sensor. They first tried cleaning it but ended up having to replace it since it was pretty worn out. The mechanic showed me the old one and you could see the buildup on it. Cost me about half of what I was worried it might, and the car's running smooth as butter now. That jerking is completely gone and it feels way more responsive. Really glad it wasn't something more serious with the ECU or fuel system. That tip about the battery disconnect was helpful too, I actually tried it before taking it in and noticed a temporary improvement, just like you said it would. Really appreciate everyone's help with diagnosing this. Always good to have some knowledge before heading to the workshop!