Z4 Valvetronic Malfunction: Rough Running & Poor Response

Hey there! I experienced almost identical symptoms with my 2019 BMW M240i last year. The rough running, hesitation during acceleration, and increased fuel consumption were exactly what I dealt with. After taking it to a certified BMW workshop, they diagnosed it as a faulty Valvetronic motor and actuator. It was indeed a serious issue that required immediate attention since it affects the engine's breathing system. In my case, they had to replace the entire Valvetronic mechanism and perform a complete system run-in. The repair wasn't a quick fix, my car stayed at the garage for three days as they needed to calibrate the new system properly. It's definitely not something I'd recommend having done at a regular mechanic since it requires specific diagnostic tools and expertise. Since the repair, my car has been running perfectly smooth with normal fuel consumption. I'd strongly suggest getting it checked at a certified BMW dealer given how critical the Valvetronic system is to the engine's performance. Hope this helps with your decision.

Hey, thanks for sharing your experience! That's really helpful since it matches what I'm going through. Just curious, do you remember roughly how much you ended up paying for the whole repair? And has everything stayed running smoothly since then, or have you noticed any other quirks pop up? I want to be prepared before I head to the dealer.

Hey again! Just wanted to give you a quick update since you asked about the costs and long-term results. The total bill came to 575 € for fixing the Valvetronic mechanism. And I've got some good news, since getting it sorted at the dealer, my car's been running like a dream! No more jerky acceleration, rough idling, or any of those annoying symptoms we discussed. The repair was definitely worth every penny. My fuel consumption is back to normal, and the engine feels as smooth as it did when I first got the car. Haven't had a single problem with the Valvetronic system since the fix, and it's been over a year now. The mechanics really knew what they were doing with the calibration and run-in procedure. Trust me, once you get it fixed at a proper BMW dealer, you'll notice the difference immediately. And based on my experience, you won't have to worry about this issue coming back. Let me know how it goes when you get yours sorted!

Thanks so much for all the detailed info! Just got back from the dealer actually, and you were spot on about everything. The repair cost was a bit higher for me, around 650 €, but totally worth it. They found the same issue with the Valvetronic motor and fixed it up in about four days. Took it for a proper drive yesterday and wow, what a difference! The car feels completely transformed, smooth acceleration, no more jerking, and my fuel gauge isn't dropping like a rock anymore. The service manager explained everything clearly, and they even gave me a detailed report of what they did. Really glad I listened to your advice about going to the dealer instead of my usual mechanic. They definitely knew their stuff, and the quality of work shows. Thanks again for helping me avoid a potential headache with a non-certified shop. You saved me from making the wrong choice!