Bmw 325ci coolant light
I drive a 2005 bmw 325ci. Recently my
coolant light had been turning on and off
whenever I use the heater. They just replaced
the thermostat and radiator hose thinking
that was the cause. But the light has come
back on again and it only comes on when the
heater is turned on but the light turns off
when the heater is off. So what could it be
this time ?