BMW XM Coolant Warning Creates Owner's Service Dilemma

Hey there! I had nearly identical symptoms with my 2019 BMW X7 M50i last month. The coolant temp warning alongside the check engine light turned out to be a faulty connection in the wiring harness to the coolant temperature sensor. It wasn't actually a coolant issue at all. The mechanic showed me that the connector had corroded, causing intermittent signal problems. Since your XM is newer, it could be something similar. They had to replace the wiring connector and recalibrate the sensor. Not a serious repair, but definitely needs proper diagnostic equipment to confirm. I'd check the coolant level first just to be safe. If it's fine, it's likely electrical. Make sure whoever looks at it has experience with BMW diagnostic systems, that's crucial for these newer models.

Thanks for sharing that! Glad to hear it wasn't anything too major with your X7. I'm gonna check my coolant level tonight just to rule that out. Your experience gives me some hope it might just be a connector issue rather than something worse. Quick question, do you remember roughly how much the repair set you back? Also, has everything been running smooth since they fixed it? Just trying to get an idea of what I might be looking at here.

Hey Steve! Happy to help out! After getting my X7 checked out last month, it did turn out the coolant level was a bit low, but the main culprit was definitely that faulty cable connection we talked about. The whole thing set me back 95 €, pretty reasonable considering I was worried it might be something way more serious! I'm pleased to report my car's been running like a dream since the fix. Not a single warning light or temperature issue since then. The mechanic did a thorough job checking everything while they had it in, and honestly, it was worth every penny for the peace of mind alone. Looking back, I was probably as worried as you are now, but these newer BMWs are pretty good at flagging issues before they become major problems. Hope you get yours sorted soon, sounds like it might be something similar to what I dealt with. Catch you around the forum! Mark

Thanks so much! Just wanted to update everyone, I took your advice and got it checked out. Turned out my situation was a bit different from yours. The mechanic found a small crack in the coolant reservoir that was causing a slow leak. They showed me exactly where the problem was, which I really appreciated after my previous bad experiences. The repair was straightforward, they replaced the reservoir and did a coolant system pressure test to make sure everything was sealed properly. Cost me about 250 for parts and labor. Not too bad considering what I was worried it might be! The car's running perfectly now, no more warning lights or temperature issues. Really glad I didn't put off getting it checked. Lesson learned about not letting past bad experiences with mechanics stop me from addressing problems early. Thanks again for all the help and sharing your experience. It really helped me feel more confident about getting it sorted.