BMW 5 Series Start-Stop Issues: Common Causes & Fixes

Hey! Some experience with BMWs here. Had a similar issue with my 2003 BMW 3 series (pre start-stop era). It was really frustrating when the engine would out of nowhere cut off. Turned out my battery was severely discharged and damaged. Had to take it to my trusted workshop, they ran diagnostics and confirmed it. Got it replaced and it solved all those weird electrical issues and warning lights. Total bill was around 290 Euro including labor and a new battery. Before you head to the shop though, could you share: Which engine variant you have? How old is your current battery? Are you getting any specific error codes? This info would help compare if we're dealing with the same problem. BMWs can be pretty sensitive to electrical issues, especially the 5 series.

Thanks for sharing your experience! I've got the gasoline engine variant, and my current battery is about 4 years old. Just had my latest service done recently at 39145 KM. You might be onto something with the battery issue, I've noticed the car's been a bit sluggish when starting up lately too. Haven't checked the specific error codes yet, but the warning light is orange and constant. Makes sense what you're saying about electrical issues in BMWs. Might get the battery checked first before diving into more complex fixes. Were there any warning signs before your battery completely gave up?

Hey again! Yes, absolutely, thinking back to my battery issues, there were definitely some warning signs. My car started showing similar symptoms to what you're describing. The sluggish start-up you mentioned? That's exactly what I experienced before things got worse. About 2-3 weeks before my battery completely gave up, I noticed the car would sometimes take an extra second or two to start in the mornings. The electrical systems would also act a bit weird, like the power windows would move slower than usual, and the radio would occasionally reset itself. Since your battery is around 4 years old, it's definitely in the replacement zone, especially for a BMW. These cars are pretty power-hungry with all their electrical systems. My mechanic actually told me that 4-5 years is typically when BMW batteries start showing their age. Given your symptoms are so similar to what I dealt with, I'd bet money it's the same issue. The constant orange warning light is another classic sign. Would definitely recommend getting the battery tested ASAP, it's way better to replace it before you end up stranded somewhere like I did! When you get it checked, make sure they do a proper load test, not just a voltage check. That's what caught my issue, the battery showed okay voltage when static but couldn't handle the load when needed.

Thanks so much for all this detailed info! You've definitely convinced me to get the battery checked right away. Those extra symptoms you mentioned, the slow power windows and radio resetting, I've actually noticed those too but didn't connect the dots until now. Really appreciate you sharing about the load test too, that's super helpful. I'll call my mechanic tomorrow and specifically ask for a battery load test. Better to deal with this now than end up stuck somewhere with a dead car. The fact that your BMW had such similar issues and a new battery fixed everything makes me feel a lot more confident about what I'm dealing with. Thanks again for taking the time to help out! I'll probably need to start budgeting for a new battery, but at least it's not something more serious. I'll update here once I get it checked out in case anyone else runs into the same problem.