M2 Surging Power Issues: Boost Control Problems?

I had a pretty similar issue with my 2014 M4 last year (some car experience here). The symptoms you're describing sound exactly like what I went through, jerky acceleration, poor fuel economy, and that annoying CEL. Took it to my regular workshop and they diagnosed a faulty vacuum switching valve. It was messing with the boost control system. The fix wasn't too complex, they replaced the valve and recalibrated the system. Cost me around 140 Euro total, including labor. Car's been running smooth as butter since then. What's your current mileage? Also, does the problem get worse when the engine is warm? This could help confirm if we're dealing with the same issue. If you want, I can share more specific details about the repair process.

Thanks for sharing your experience with the M4! My M2 is currently at 164245 KM and just had its regular service last month. The issue definitely gets more noticeable when the engine's warm, especially during highway pulls. It's reassuring to hear that your fix was relatively straightforward and not too expensive. I'll get the vacuum switching valve checked out, that could explain my symptoms perfectly. Did you notice any specific boost pressure readings on your car before the repair?

Yeah, actually I did keep an eye on the boost readings before getting it fixed! With my M4, I was seeing really inconsistent numbers, normally it should hold steady around 1 bar under load, but it was fluctuating between 0.4 and 0.8 bar. Totally unstable. Your mileage is pretty close to what mine was when this happened (I was around 158000 KM). The warm engine behavior you're describing is exactly what I experienced too. Those highway pulls were particularly frustrating, it felt like the car couldn't make up its mind about how much power to deliver. I remember this one time trying to pass someone and the car just fell flat on its face. Pretty scary stuff. Quick tip though, when you get it checked, have them look at the wastegate actuator too. My mechanic said these issues sometimes come as a pair. I got lucky and only needed the vacuum valve, but it's worth checking both while they're in there. Been about 15 months since my repair and haven't had a single issue since. The difference in performance was like night and day!

Thanks for all that detailed info! You've basically described my exact situation with those boost readings, I checked mine today and saw similar wonky fluctuations. It's actually a relief to hear that your fix has held up for 15 months now. I'll definitely get both the vacuum valve and wastegate actuator checked out this week. Been avoiding highway overtakes lately because of that exact scenario you mentioned, really don't want to get caught with sudden power loss when I need it most. Was starting to worry this might be something major, but knowing your repair was straightforward gives me hope. Will let the mechanic know about your experience too, always helps them to have a starting point for diagnosis. Really appreciate the detailed explanation of what to expect!