BMW M4 Power Loss and Rough Running Baffles Owner

Hey there! I had nearly identical issues with my 2015 BMW M3 last year. The symptoms you're describing match exactly what I experienced, power loss, rough running, and jerky acceleration. After diagnostic tests, it turned out to be a faulty fuel injector. One of the injectors wasn't spraying fuel properly, causing the engine to run lean in that cylinder. The diagnostic code specifically pointed to the injection system. In my case, it was a serious issue that needed immediate attention because running lean can potentially damage other engine components if left unchecked. The garage had to replace the defective injector and reprogram the engine management system. I'd strongly suggest getting it checked soon, these symptoms typically don't resolve themselves and can lead to bigger problems. The M engines are sensitive to fuel delivery issues. Good luck with the fix.

Hey, that's really helpful info! Had literally the same thing happen with my M4. My injector problem got sorted about 6 months ago, and it's been running like a dream since then. Can't remember exactly what the total damage was though, would you mind sharing what you paid for the fix? Also curious if you've had any other problems since getting it repaired? Mine's been perfect, but always good to know what to watch out for with these beasts.

Hey again! Glad I could help and happy to hear you got yours fixed too! Yeah, I remember the numbers pretty well, set me back 515 € all in, including the new injector and programming work. Honestly, it was worth every penny because the car's been running amazingly since then. The lean running issue is completely gone now, got that sorted with the injector replacement. You know how these M engines can be picky, but once you get them dialed in right, they're absolute monsters (in a good way!). Haven't had a single issue since the fix, and it's been about a year and a half now. The power delivery is smooth as butter, no more jerking or rough running. Sounds like you're having the same good experience with yours post-repair. These M cars are pretty solid once you sort out any niggles. Just keep up with regular maintenance, and she should keep purring like a kitten and roaring like a lion when you want her to!

Thanks for sharing that info about the repair cost! Actually, my bill was pretty close to yours. The shop really did fix it up perfectly, no more jerking or power loss issues at all. Speaking of the repair experience, I gotta tell you what happened at the shop. When I first took it in, the mechanic knew exactly what to look for after hearing those symptoms. He hooked up the diagnostic tool and spotted the injector problem right away. What really impressed me was how they took the time to show me the faulty injector after removing it, you could actually see the wear that was causing the spray pattern to be all wrong. They had it fixed within a day, and the difference was night and day. The car's back to being that smooth, powerful beast we all love. Been about half a year now with zero issues. Think I've finally found a mechanic I can trust with my M4. Again, thanks for sharing your experience. It's always reassuring to hear similar stories with happy endings!