BMW M3 Cold Start Nightmare: Solutions & Advice Needed

Hey there! I faced almost identical issues with my 2015 BMW M4 last winter. The symptoms were spot on, sluggish warm-up, rough idle when cold, and higher fuel consumption. Got the same error code too. Took it to the garage and they confirmed it was indeed the PTC auxiliary heater. The heating element was failing, causing the system to work inefficiently. It was a serious job since they had to remove several components to access the heater assembly. The repair took about 6 hours. The fix made a huge difference, car now warms up properly in cold weather, idles smoothly, and fuel consumption is back to normal. Just make sure you get a mechanic who knows BMW heating systems well, it's not a job for a general repair shop. Best of luck with yours.

Thanks for sharing your experience! That's exactly what I needed to hear. My symptoms match yours perfectly. Quick question, do you remember roughly how much you ended up paying for the repair? Also, has everything been running smoothly since the fix, or have you noticed any other issues pop up? I'm trying to budget for this and want to make sure I'm prepared for any potential follow-up problems.

Hey again! Just wanted to follow up, I had the PTC heater fixed and it cost me 350 € all in. Honestly, it was worth every penny! The car's running like a dream now. All those annoying issues, the slow warm-up, rough running, and high fuel consumption, they're completely gone. Since getting it sorted about three months ago, everything's been perfect. No new problems have shown up, and the engine warms up quickly even on the coldest mornings. Fuel economy's back to where it should be too. I'd definitely recommend getting it done sooner rather than later. It's one of those repairs that makes a real difference to how the car runs, and leaving it too long might cause other problems. Plus, being able to get into a properly warm car on a cold morning is pretty nice! Feel free to ask if you need any other info about the repair. The mechanic did a great job explaining everything to me, so I might be able to help with specific questions.

Thanks a lot for the detailed info! I finally got around to getting my car fixed yesterday, and what a difference! The mechanic I found did a fantastic job, completely different from my last experience. Took about 5 hours for the whole repair, and they charged me a bit more at 400 €, but it was totally worth it. The car's running like new now. Started up this morning and warmed up in no time, such a relief after dealing with those cold start issues for so long. No more rough idling, and I can already tell the fuel consumption's better. They even showed me the old PTC heater, it was pretty worn out. Really glad I didn't put this off any longer. And hey, thanks again for helping me diagnose the problem, saved me from going around in circles with different mechanics. The repair was exactly what it needed. I'll definitely be sticking with this new mechanic for future services. Best decision I've made for my car in a while!