Originally posted by projectSHO89:
Coolant strength or concentration has absolutely nothing to do with the coolant light.

It is a simple level sensor. If the tank is slightly overfull (or more), the vehicle is level, and the coolant light is still on, then the sensor is faulty.

The coolant light should come on during "bulb prove-out", then go out if everything is normal. Has absolutely nothing to do with the engine operating temp. In that particular case, it was due to a low level (due to the leak). The coolant expanded enough after engine warmup to "make" the sensor.

Steve



I beg to differ.

At 30% glycol (about 50 -50 solution), the specific gravity of the coolant is about 1.038. Pure water is 1.000. As the Contour's sensor is very sensitive (or finicky), the lower SG will cause the sensor not to rise (per your simple level sensor theory).

As for the cool engine before checking level, I have seen levels being lower than max line when engine is cool and then the level rising after being warmed up (once again, completely consistent with your "coolant expanded enough after the engine warmup to 'make' the sensor" theory).

"Always do the cheap and easy ones first." 1996 V6 ATX 96K miles