BMW 5 Hybrid Cooling System Issues, Help Needed

Hey there! I had almost the same issue with my 2021 BMW 3 Series Hybrid last winter. The symptoms were identical, weird temp readings, check engine light, slow warm-up. I first checked the cooling grille myself but that wasn't it. Took it to my regular workshop and turns out it was just a blown fuse connected to the temperature sensor system. Quick 52 euro fix and everything went back to normal. The mechanic mentioned this is pretty common in BMW hybrids. Before I jump to conclusions though, can you tell me if you notice any other warning lights or unusual behavior? Also, did you scan for error codes? This would help narrow down if you're dealing with the same issue I had. If you want, I can share more details about the specific fuse location, just let me know which 5 Series variant you have (520e, 530e, etc.).

Thanks for sharing your experience! My car's at 165876 KM and had its last service about 2 months ago. I'm seeing exactly those same symptoms you described, no other warning lights though. Haven't scanned for error codes yet since I wanted to check with the community first. Mine's a 530e, so I'd really appreciate if you could share the fuse location details. Seems like a much better starting point than taking it straight to the dealership. Did your mechanic mention why these fuses tend to blow in the hybrids specifically?

Hey again! Glad to help further with your 530e issue. Since I had the same problem with my 3 Series, I can definitely share more details. In my case, the fuse box you need to check is under the glove compartment, it's fuse number 42 (15A rating). But honestly, even though it fixed my issue, I'd still recommend getting those error codes read first just to be 100% sure. Better safe than sorry, right? About your question on why these fuses blow in hybrids, my mechanic explained that it's related to the constant switching between electric and combustion modes. Apparently, this puts extra stress on the temperature monitoring system, which can cause the fuse to blow over time. Makes sense considering the complexity of hybrid powertrains. One thing I forgot to mention in my first reply, before changing the fuse, my mechanic tested the sensor itself to make sure it wasn't faulty. With your mileage being similar to what mine was when I had the issue, it's looking more and more like we had the same problem. Let me know how it goes after checking the fuse. If it turns out to be something different, I'm curious to know what it is!

Thanks so much for all the detailed info! I just checked fuse 42 and you won't believe it, it was actually blown! I replaced it with a spare 15A fuse I had in my toolkit, and the temperature readings are back to normal. The check engine light turned off after a short drive too. What you mentioned about the hybrid system causing extra stress on the temperature monitoring makes total sense. I've owned conventional BMWs before, and this is the first time I've encountered this kind of issue. Really glad it turned out to be such a simple fix rather than something major with the cooling system. You saved me a potentially expensive and unnecessary trip to the dealership. Definitely keeping spare fuses in the car from now on. Really appreciate you taking the time to share all this information, it's exactly why I love asking the community first!