Sunnyinhollister,
Yes. Our 2013 Cruzes, whether MT equipped, like yours, or AT, like mine, have revised OLM calibration, unlike this earlier model.
So it's pure speculation as to how low the OLM was, but I still believe it had hit 0% sometime before this mess occurred.
The 1.4L Turbo has active cooling, like the new 2.5L Ecotec engine. It utilizes an electric heating unit mounted internally on the thermostat housing. The ECU allows the water temperature to rise during light load conditions to lower emissions and slightly improve gas mileage.
As the load increases, the coil is energized, heating the housing, "tricking" the internal wax pellet of the thermostat to open the thermostat valve, just as if the coolant temperature had raised. This lowers the coolant temperature, particularly that flowing to the heads, which all GM engines do now, reverse cooling. The heads cool off, limiting detonation, and lowering octane requirements. As the water passes through the head coolant passages and absorbs heat, then enters the block at higher temperatures now. A hot block is a stable, happy, low wearing block.
The engine also has a water/oil heat exchanger. Coolant is routed around the cartridge oil filter housing, warming the oil on startup, when the oil is cold. Later during hot engine operation, especially under boost, as the oil temperature rises, due to horsepower being created, and the oil jets spraying oil on the pistons keeping them relatively cool, the water/oil heat exchanger keeps the oil-water delta within 10 degrees fahrenheit.
Cool stuff.
Gary