BMW 8 Cooling Issues, Active Grille Behind Problems?

Hey there! I had a similar issue with my 2018 BMW 7 diesel last winter. I'd say I have some experience working with cars, though I'm no expert. Your symptoms sound exactly like what I faced! My trusted workshop discovered it was just a blown fuse controlling the temperature sensors. Pretty simple fix, cost me around 52 Euro including labor. The mechanic explained that these fuses can sometimes fail, causing weird temp readings and triggering the check engine light. Before you head to a workshop though, could you share: How long has this been happening? Does the temperature gauge fluctuate or stay stuck? Have you noticed any actual cooling issues? Might help pinpoint if you're dealing with the same problem I had. Let me know and I'll try to help further!

Thanks for the feedback! I had this issue for about 2 weeks now. The temperature gauge keeps jumping between cold and halfway out of nowhere, never reaching normal operating temperature. Last service was at 150937 KM and everything was fine then. Haven't noticed any real overheating, but the engine's definitely taking longer to warm up than usual. I'll check the fuses first before booking a workshop appointment. Really hoping it's just a simple fix like yours and not something more serious with the cooling system.

Hey again! Thanks for those details, that unusual temperature jumping is exactly what I experienced! After you mentioned the mileage, I remembered my issue started around 145000 KM, so pretty similar to yours. I initially thought it was just the cooling grille too (that was my first guess in your original post), but when the mechanic checked the fuses, we found the culprit. It's box 3, fuse 27 in our BMWs if you want to check yourself. Make sure the engine's cold and the key's out before poking around in there though! Just a heads up, if checking the fuse doesn't solve it, there might be a loose connection in the wiring harness. My mechanic mentioned this was the next thing he would've checked if the fuse wasn't the issue. The good news is that since you're not seeing any actual overheating, it's probably just a sensor/electrical thing like mine was. Would love to hear what you find when you check those fuses. The fact that your temps are jumping around rather than staying stuck really makes me think it's the same electrical issue I had. Keep us posted on what you find!

Thanks so much for the detailed help! Just checked fuse 27 in box 3, and wouldn't you believe it, it was blown! Replaced it with a spare I had lying around, and the temperature gauge is now working perfectly normal. Engine's warming up like it should, and the check engine light turned off after a short drive. Really saved me from an expensive workshop visit there. It's amazing how such a small thing can cause so much worry. Total cost: less than 5 bucks for a new fuse versus what could have been hundreds at the dealer. And here I was thinking it might be something major with the cooling system! Really appreciate you taking the time to share your experience. Will definitely keep an eye on that fuse box for any future issues. Thanks again for pointing me in the right direction!