BMW 5 Series Hybrid: Engine Jerking and Power Loss Issues

Hey there! I have some experience working on cars, and I actually faced a similar issue with my 2011 BMW ActiveHybrid 7. Like you, I experienced jerking and reduced power, which really concerned me. Took it to my trusted workshop and found out it was due to a botched chip tuning job from a third-party tuner I'd used earlier. The fix involved resetting the ECU and reinstalling the original factory settings, which cost me about 180 Euro. After that, the car ran smooth as butter again. Your symptoms sound very familiar to what I went through, but to help better, could you share: Have you had any recent modifications or tuning done? Are there any specific conditions when the jerking occurs (cold start, high speeds, etc.)? Which fault code is showing up? By the way, if you're considering the BMW 7 Series, it's also worth checking out, quite similar in terms of hybrid system architecture.

Thanks for sharing your experience! My situation might be a bit different since I haven't done any modifications or tuning to my car. Just had my latest service about 3 months ago and currently at 22016 KM. The jerking mostly happens when I accelerate, especially from a complete stop. It feels like the car is struggling to deliver power smoothly. Haven't checked the exact fault code yet, but planning to get it scanned tomorrow. Really helpful to know about your ECU experience though, will definitely keep that in mind when discussing with the mechanic. Did you notice any warning lights on the dash before getting it fixed?

Hey again! Thanks for providing those additional details about your situation. Since you mentioned you haven't done any modifications, I'm thinking your issue might be different from what I experienced with my BMW ActiveHybrid 7. In my case, before the ECU reset fixed everything, I did see the check engine light and a battery warning icon on the dash. The jerking in my car was actually most noticeable during medium acceleration, like when trying to pass other cars on the highway. Given what you're describing, especially the jerking from a complete stop, I'm wondering if it might be related to the hybrid system's transition between electric and combustion power. After my ECU incident, I've become pretty familiar with these cars, and that transition point can be tricky if certain sensors aren't working properly. One thing I learned from my experience, don't wait too long to get it checked out. These hybrid systems are complex, and small issues can sometimes cascade into bigger problems. Let us know what the scan reveals tomorrow. Really curious to hear what fault code you're getting since it might help others who run into similar issues with these models. Would be great if you could share the diagnostic results when you get them. Even though my issue turned out to be tuning-related, I've picked up quite a bit of knowledge about these cars along the way!

Thanks so much for the detailed follow-up! You've made a really good point about the hybrid system transition, that actually makes a lot of sense given when I'm experiencing the problems. I didn't have any warning lights initially, but just this morning the check engine light finally came on, so I guess it's definitely time to get it looked at. Really appreciate you sharing all your knowledge about these cars. It's super helpful to have some background info before heading to the mechanic. I'll definitely post an update once I get the diagnostic results tomorrow. Even though our issues might be different, it's great to learn from other people's experiences with these hybrid BMWs. Thanks again for taking the time to help out!