BMW Coolant Warning + Check Engine: Expert Help Needed

I had almost identical issues with my 2006 BMW 7 Series last month. The coolant temp warning and check engine combo turned out to be a faulty wiring harness connection to the coolant temp sensor. My mechanic found that the connector was corroded and wasn't making proper contact. The diagnostic revealed similar fault codes. They had to replace the wiring harness and the sensor itself since there was some damage. It wasn't a major repair, but leaving it unchecked could have led to engine overheating issues. Make sure to get it checked soon though. These symptoms typically don't resolve themselves and can lead to bigger problems if ignored. In my case, it wasn't related to low coolant at all, though that's always worth checking first. Just wanted to add, if you do need the sensor replaced, have them check the surrounding connections too. Mine showed signs of wear in other nearby connectors, so I had those preventively serviced while they were in there.

Thanks so much for sharing your experience! It's really helpful to know it was the wiring harness and sensor in your case. I'll definitely check the connections and surrounding areas as you suggested. Just curious, do you remember roughly how much you ended up paying for the repair? Also, has everything been running smoothly since then or have you noticed any other issues pop up?

Hey there! Happy to give you an update. Just had mine fixed last week, cost me 95 € for the cable/connector repair, which was actually less than I expected. They also topped up the coolant while they were at it since it was running a bit low. Everything's been running perfectly since the fix, no more warning lights, and the engine temp is staying exactly where it should be. Such a relief! My mechanic mentioned I was lucky to bring it in when I did, as these things can sometimes spiral into bigger issues if left unchecked. The best part is how straightforward the repair turned out to be. I was initially worried it might be something major, but nope, just needed that connection sorted and fresh coolant. Money well spent if you ask me. Definitely recommend getting yours checked out soon. These BMWs are pretty solid cars overall, but they do need proper attention when these warning lights pop up. Let us know how it goes when you get it looked at!

Thanks for all the helpful info! Just wanted to update you all on what happened. I finally got the nerve to try a new mechanic, and I'm so glad I did! The guy was super honest and fixed it right away. Turned out my issue was pretty similar, faulty sensor connections and a bit of corrosion. The repair was quick and cost about what you mentioned. Fixed the wiring, replaced the sensor, and topped off the coolant. The whole thing took less than two hours. What a relief it wasn't something more serious! My BMW's running like a charm now, no more warning lights or temperature issues. Should've done this weeks ago instead of worrying about it. Guess sometimes you just need a push to try a new mechanic, and this time it really paid off. Thanks again for helping me make the decision to get it checked out!