vitalsigns
6120
Cooling system was a common weak point for BMW cars for years.
Feb 28, 2021,18:26 PM
Certainly better on newer cars, and 57K miles is very early, but my guess is a water pump failure (could be a temp sensor too, but they are designed to fail open and therefore lead to overcooling instead of undercooling). This usually doesn't happen until closer to 100K miles.
Mine failed on an earlier BMW at around 90K miles.
I recently had a temperature sensor issue on a different BMW. The temp sensor is essentially right at the water pump, so I had my water pump replaced prophylactically (70K miles). It's not an expensive part, and virtually all the cost is already spent on labor getting to the temp sensor.
Good luck!
That's a fun car, by the way. I really enjoyed driving it at a BMW track driving event.
Cheers,
John