BMW 7 Diesel Overheating, Electric Fan Failure?

I've got some experience working with BMWs, and I actually faced something similar with my 2014 BMW 5 Series diesel. My workshop discovered it was just a faulty wiring connection to the cooling fan, the plug wasn't making proper contact anymore. Had to pay 95 Euro to get it sorted, but it was worth it to prevent any engine damage. What I first noticed was pretty much exactly what you're describing, overheating warnings and limp mode. Once they found the loose connection and fixed it, everything went back to normal. What's your mileage on that 7 Series? Also, have you noticed if the fan is running at all when the car is stationary? This info would help me understand if you're dealing with the same issue I had.

Thanks for sharing your experience! Mine's at 121103 KM and had its last service about 2 months ago. The fan seems to run intermittently, sometimes it kicks in, other times it's completely dead. I'm thinking it might be similar to your wiring issue. I'm planning to get it checked out this week, but I wanted to gather some insights from the community first. The temperature gauge goes up pretty quickly, especially in slow-moving traffic. It's a bit nerve-wracking to drive like this. Hopefully, it's just a simple fix like yours was.

Hey again! That intermittent fan behavior you're describing sounds exactly like what I experienced. The symptoms match perfectly, especially the quick temperature rise in slow traffic. That's a classic sign. Looking back at my case, I can tell you the intermittent operation was what really confirmed it was electrical rather than a mechanical fan failure. My mechanic explained that when the connection was getting hot, it would expand and lose contact, which is why it worked sometimes and not others. One thing I didn't mention in my first reply, before I got it fixed, I noticed that sometimes giving the engine bay a light tap near the fan connection would temporarily get it working again (though I wouldn't recommend trying this as a solution!). That was another clue it was definitely a connection issue. With your mileage being similar to what mine was when I had the problem (I was at about 118000 KM), and given the similar symptoms, I'd put money on it being the same issue. I'd suggest having them check the wiring harness and connection points first before replacing any major parts. Just keep an eye on that temp gauge until you get it sorted. If you notice it climbing too high, better to pull over and let it cool down than risk any engine damage. Keep us posted on what they find!

Thanks so much for the detailed follow-up! That's really interesting about the tapping trick, I actually noticed something similar when my mechanic was looking at it earlier today. You were spot on, they found a corroded wiring connector that was causing the intermittent fan issues. The repair bill came to about 120 for parts and labor, which isn't too bad considering what could've gone wrong with the engine if left unfixed. They also mentioned finding some debris around the radiator area that wasn't helping the situation, so they cleaned that out too. The car's running perfectly now, no more temperature spikes, even in stop-and-go traffic. The fan kicks in consistently when it should, and the emergency mode hasn't come back. Really appreciate everyone's help here, especially your detailed explanation of your experience. It definitely helped me understand what I was dealing with and made me feel better about the whole situation.