BMW i8 Coolant Warning Signals: Hybrid Help Needed

Hey there! I had a similar issue with my 2015 BMW i3 hybrid last month. The coolant temp warning appeared alongside the check engine light. Turned out the connector plug for the coolant temperature sensor was corroded and had a loose connection. The issues you're describing sound familiar. My previous experience taught me that these symptoms shouldn't be ignored, coolant problems can escalate quickly in hybrid systems. Took it to a certified hybrid specialist who found the faulty connection. They had to clean the connector, replace the damaged pins, and reseal it properly. The repair itself wasn't major, but leaving it unchecked could have led to more serious engine damage. The whole diagnostic and repair process took about 3-4 hours. Make sure whoever works on it has specific experience with BMW hybrid cooling systems, these aren't like conventional engines. My advice would be to stick with certified techs who specialize in hybrid BMWs. The cooling system in these cars is complex and interlinked with both the electric and combustion components. Hope this helps with your decision.

Thanks for sharing your experience! That does sound pretty similar to what I'm dealing with. Really good to know it wasn't something catastrophic in your case. Just curious, do you remember roughly how much you ended up paying for the fix? Also, has everything been running smoothly since the repair, or have you noticed any other issues pop up? Thanks!

Hey again! Happy to update you! The repair actually came to 95 € total, which honestly wasn't as bad as I was fearing. The main issue was indeed just that faulty cable connection to the coolant sensor. They also topped up the coolant while they were at it, since it was running a bit low. I'm pleased to report that everything's been running like a dream since then, no warning lights, no temperature issues, nothing! It's been about six weeks now, and my i3 is purring along perfectly. Such a relief it wasn't anything more serious. These hybrid systems can be tricky, but sometimes it's just these small electrical gremlins that cause the warnings. Best advice I can give is to get it sorted sooner rather than later. The peace of mind is worth it, and catching these things early usually means avoiding bigger problems down the road. The coolant system in these hybrids is pretty sophisticated, so you definitely want it working properly. Let me know how yours turns out!

Thanks so much for the follow-up! Finally got my i8 checked out yesterday and you wouldn't believe it, it was almost exactly what you described. The mechanic found a corroded connector and some dodgy wiring near the coolant sensor. Total bill came to a bit more than yours at 150 € since they had to replace the entire sensor unit, but honestly, I'm just relieved it wasn't worse. The guy explained everything clearly, showed me the old parts, and even gave me some tips about preventive maintenance. No more warning lights since the fix, and the engine's running smoother than before. Really glad I didn't put this off any longer. Thanks again for sharing your experience, it really helped me feel more confident about getting it sorted. Funny how these fancy hybrid systems can get thrown off by something as simple as a corroded wire! At least now I know what to watch out for in the future. Best decision I made was finding this new mechanic. Sometimes you just need that push to make a change, you know?