BMW i3 Hybrid Heat & Engine Issues, Bad Bypass Valve?

Hey there! I've got some experience with hybrids, having dealt with a similar issue on my 2019 BMW i8. This sounds very familiar, I had almost identical symptoms. Turned out the previous repair work on my cooling system wasn't done properly, which led to these heating issues. The best part? The workshop fixed it for free since it was their mistake from a previous repair. Before I share more specifics about my case, could you share: When was your last cooling system service? Which error codes are you getting? Is the temperature gauge steady or fluctuating? These details would help me give you more relevant advice from my experience. BMW products can be tricky with their cooling systems, especially the hybrid models like our i3 and i8.

Thanks for your response! I just had my last service about 3 months ago at 73717 KM. The error codes I'm getting are P1434 and P0597, and the temperature gauge keeps jumping up and down pretty out of nowhere. It's really frustrating because I've always been careful with maintenance. The thing that worries me most is that this started happening right after the last service, which makes me wonder if something wasn't put back together properly. I've got all the service records if that helps. My mechanic's booked solid for the next two weeks, so I'm trying to figure out if this is something I need to get looked at urgently or if it can wait.

Hey again! Thanks for those details, this is getting more interesting by the minute. You know what? Your situation is even more similar to what I experienced than I initially thought. My i8 started acting up right after a service too, and I had almost the exact same error codes. The jumping temperature gauge combined with those specific codes really rings a bell. In my case, it turned out the technician hadn't properly secured a coolant hose connection during the service. They also didn't bleed the cooling system correctly, which caused air pockets. That's what was making my temp gauge go crazy just like yours. Given my experience, I'd strongly suggest not waiting those two weeks. These symptoms in hybrid BMWs can lead to bigger issues if left unchecked. Can't tell you how glad I am that I didn't wait, my mechanic told me I could've ended up with some serious damage to the electric drive components. Here's what I'd do: Call your service center and explain that these issues started right after their service. Mention the error codes and that you've got another hybrid BMW owner (me) who had the same problem due to improper service work. They might be more willing to squeeze you in sooner, especially since it could be related to their recent work. Trust me, you don't want to mess around with cooling issues in these hybrids. They're awesome cars but pretty complex when it comes to thermal management.

Thanks so much for the detailed response, this is exactly the kind of insight I was hoping for! You've actually made me feel both better and more concerned at the same time. Better because now I know I'm not imagining things about the service timing being suspicious, but concerned enough to take action right away. I just called the service center and mentioned everything you suggested, including the similar case with your i8. You were right, they're fitting me in tomorrow morning! They seemed pretty interested when I mentioned those specific error codes and the connection to recent service work. Really appreciate you taking the time to share your experience. It's given me the confidence to push for immediate attention rather than waiting those two weeks. I'll definitely update you once they've checked it out, hopefully it's just a simple fix like yours was. These hybrids are amazing but you're absolutely right about their complexity!