BMW M4 Alternator Warning Signs, What You Need To Know

Hey there! I had almost identical issues with my 2016 BMW M3 last summer. The symptoms matched yours perfectly, dim lights, struggling to start, and battery warnings. Initially thought it was just the battery, but turned out to be the generator (alternator) that was failing. Had it checked at the garage, and the diagnostic confirmed my suspicions. The generator's voltage regulator was shot, and the bearing was making noise. They had to replace the entire generator unit since these parts aren't sold separately on BMWs. It's definitely a serious issue that needs immediate attention, if the generator fails completely, you'll be stranded whenever the battery runs out. In my case, they also found the serpentine belt was showing signs of wear, so I had that replaced too while they were in there. The repair took about a day, and my M3 has been running perfectly since then. Don't wait too long on this one, driving with a failing generator can damage other electrical components in your car. Hope this helps!

Thanks a lot for sharing your experience! That's super helpful, sounds exactly like what I'm dealing with. Really glad to hear your M3 is running smoothly now. Quick question, do you remember roughly how much the repair set you back? Also, any other issues pop up since you had it fixed? Just trying to get an idea of what I'm in for. Thanks again!

Hey again! Happy to give you an update! Got my M3 fixed at the mechanic and it set me back 960 € for the generator replacement. I know it's not cheap, but honestly, it was worth every penny. The car's been running like a dream since then, not a single electrical issue in sight. No more flickering lights, battery warnings, or starting problems. The funny thing is, I didn't realize just how bad the old generator was until they put the new one in. The difference was like night and day. All those little electrical gremlins I'd been dealing with just disappeared. Even the stereo sounds clearer now that it's getting proper power! Haven't had to touch anything electrical since the repair, which was about 8 months ago now. The mechanic did a solid job, and it's been smooth sailing. Just make sure whoever does yours uses genuine BMW parts, it makes a difference with these cars. Don't stress too much about the repair, once it's done, you'll be back to enjoying that M4 properly!

Thanks so much for the detailed info! I finally bit the bullet and took my M4 to a mechanic yesterday. Man, what a day that turned out to be! The diagnostic confirmed it was the alternator, just like we thought. They had to order the part, but I got lucky, they had a cancellation and squeezed me in today. The whole repair took about five hours. Ended up costing me a bit more than yours because they found my battery was pretty much toast too, so I had them replace both. But wow, what a difference! The car feels completely transformed. No more warning lights, strong starts every time, and all the electrical systems are working perfectly. Funny how you don't realize how bad things were until they're fixed properly. Really appreciate you sharing your experience, it gave me the confidence to get this sorted before I ended up stranded somewhere. The mechanic said I made the right call coming in when I did. Guess I can stop worrying about those dashboard lights now! Thanks again for all your help!