A coolant control system of a vehicle includes a target pressure module and a thermostat valve control module. The target pressure module determines a target pressure of coolant in a coolant path between a thermostat valve and at least one of an engine oil heat exchanger and a transmission fluid heat exchanger. The thermostat valve control module closes the thermostat valve and blocks coolant flow out of an engine when a temperature of coolant within the engine is less than a predetermined temperature. When the temperature is greater than the predetermined temperature, the thermostat valve control module controls opening of the thermostat valve to the coolant path based on the target pressure.