BMW X7 Cold Start Issues, PTC Heater Problems?

Hey there! I had a pretty similar issue with my 2019 BMW X5 last winter (I also own an X3). I've got some experience working on cars, but mostly basic maintenance stuff. The symptoms you described are exactly what I faced, slow warm-up, rough cold starts, and my fuel consumption went through the roof. Took it to my regular workshop and they diagnosed a faulty electric auxiliary heater (PTC heater). The repair set me back about 350 Euro, but it fixed all the issues completely. Could you share more details about your fault code and when exactly you notice the rough running? Also, what's the outside temperature when these issues occur? This would help confirm if we're dealing with the same problem. The repair was pretty straightforward once they pinpointed the issue, took about 3-4 hours total. Haven't had any problems since then.

Thanks for sharing your experience! My X7 currently has 12000 KM on the clock and just had its latest service. The fault code I'm getting is P0597, and the rough running is most noticeable when starting up in the morning. It definitely feels worse than it did a few months back. The engine eventually smooths out after about 5-10 minutes of running. Based on what you're describing, sounds like I might be dealing with the same PTC heater issue. I'm relieved to hear it's a relatively straightforward fix. Did you notice any warning lights on the dashboard before getting it repaired? Also curious if your workshop mentioned anything about preventive measures to avoid this issue in the future. Thanks again for the help!

Hey again! Yeah, looking at those details you shared, it's definitely sounding more and more like the same PTC heater issue I dealt with. What's interesting is that your X7 is showing these symptoms at just 12000 KM, mine started acting up around 45000 KM, so you might be dealing with a premature failure. The P0597 code is exactly what my car showed too, it's specifically related to the thermostat heater control circuit. And yeah, about the warning lights, I actually didn't get any dashboard warnings until pretty late in the game. Just that rough running and the heating issues you mentioned. When my workshop did the repair, they mentioned these heaters can fail due to regular wear and tear, but they also said keeping the battery in good condition helps prevent premature failure. Apparently, voltage fluctuations can sometimes mess with the heater control module. They recommended getting the battery checked during regular services. Since getting it fixed, I've made sure to let the engine warm up properly before pushing it hard, especially in cold weather. Not sure if it makes a huge difference, but haven't had any issues since the repair. If you're experiencing the same symptoms with the same error code, I'd definitely get it checked out soon. Better to deal with it now than wait for it to potentially get worse!

Thanks so much for all the detailed information! That's really helpful to know about the connection between battery health and the PTC heater, definitely wasn't aware of that before. I've actually noticed that my battery indicator has been a bit inconsistent lately, so maybe there's a connection there. I'll make an appointment with my workshop right away and have them check both the heater and the battery. Given that my X7 is showing these issues so early, I might also see if this could be covered under warranty since it's a 2021 model. I'm glad I asked here, having your repair experience as a reference point gives me a much better idea of what to expect. Really appreciate you taking the time to explain everything in such detail, especially about the post-repair care. I'll definitely follow your advice about proper warm-up times once it's fixed. I'll update the thread once I get it sorted out in case anyone else runs into the same issue. Thanks again for all your help!