BMW 3 Hybrid Cold Start Issues, Help Needed

Hey there! I've got some experience with hybrids, though I'm no expert. I actually had a similar issue with my 2010 BMW 5 Hybrid last winter (love the BMW lineup, also owned a 7 series before). The symptoms you're describing sound exactly like what I dealt with. For me, it turned out to be corroded battery connections that weren't making proper contact. Had my trusted mechanic check it out, and they cleaned up the connections, reseated everything properly, and did a full battery terminal check. Total bill came to 155 Euro, and it's been running perfectly since then. Before jumping to conclusions though, could you share: Any other warning lights showing up? How old is your current battery? Does this happen only on cold starts, or also when the engine is warm? This could help pinpoint if we're dealing with the same issue or if something else might be going on with your 3 series.

Thanks for your detailed response! My car has about 60500 KM and had its last service about 3 months ago. I'm seeing the engine warning light come on only during cold starts, and the battery is actually pretty new, replaced it last year. Haven't noticed any other warning lights besides the engine malfunction one. The weird thing is that it runs perfectly fine once it actually starts up. Been keeping an eye on the hybrid system too, but it seems to be functioning normally after the initial start-up issues. Might take your advice about checking those battery connections though, as it does sound pretty similar to what I'm experiencing.

Hey again! Thanks for the extra details about your BMW. Since you mentioned the battery is new and you're only seeing this during cold starts, I'm starting to think it might be different from my initial battery connection guess. After you described those symptoms, it reminds me even more of another issue I had with my 5 Series Hybrid. Had similar trouble when mine was around 65000 KM, perfect running after startup but terrible cold starts. Turned out my fuel pressure regulator was acting up, and the fuel injectors needed a good cleaning. They were getting gunked up, especially noticeable in cold weather. Got that fixed about 18 months ago, cost me around 450 Euro total, but it's been starting like a charm ever since, even in freezing temps. The mechanic also mentioned checking the spark plugs while they were at it, might be worth having those looked at too. Quick question though, have you noticed any slight hesitation or rough idling in the first minute or so after those cold starts? That was another symptom I had before getting mine fixed. Just trying to see if we're dealing with the same gremlin here!

Thanks so much for sharing that extra info about the fuel pressure regulator! Come to think of it, I have noticed a bit of rough idling right after those cold starts, probably should have mentioned that earlier. It usually smooths out after about 30-40 seconds of running. That really does sound similar to what you experienced with your 5 Series. I'll definitely have my mechanic check the fuel pressure regulator and injectors when I take it in. Might as well get those spark plugs looked at too while they're at it, better safe than sorry! Really appreciate you taking the time to help me troubleshoot this. I was worried it might be something major with the hybrid system, so I'm actually feeling quite relieved now. Will let you know what they find when I get it checked out!