The coolant indictor light randomly appears on my E83 (X3). It seems to illuminate more often when the heat is turned to a certain temp and shuts off when the heat is lowered. It also will appear on increased acceleration /load such as driving up hill. The coolant level appears full according to the pop-up indicator. The engine temperature gauge does not indicate overheating. I'm thinking potential causes include sensor, thermostat, water pump (?). Comments much appreciated
The level sensor could be the issue. The sensor is on the bottom of the expansion tank. The sensors are cheap and I would start there. I have seen them leak coolant through the wiring and cause weird issues.
