Methods and systems are provided for a cooling system for a vehicle engine. In one example, the cooling system includes a coolant solution circulated through both an engine cooling circuit and a vehicle interior heating circuit that is fluidly coupled to the engine cooling circuit, and a reservoir containing concentrated antifreeze. The concentrated antifreeze is flowed from the reservoir to the vehicle interior heating circuit via a shutoff valve to increase a concentration of antifreeze in the coolant solution. In some embodiments, a separation unit may be used to decrease the concentration of antifreeze in the coolant solution.

Methods and systems are provided for maintaining a desired engine coolant level and a relative glycol amount in the engine coolant by using water sourced from on-board vehicle systems. In one example, a method may include supplying water to the engine coolant reservoir in response to the engine coolant level decreasing below a threshold. Also, a relative glycol amount in the coolant may be maintained at a threshold amount by adding water to the coolant in response to a relative glycol increasing above the threshold.

An example device in accordance with an aspect of the present disclosure includes a sensor, a controller, and an injector. The sensor is to provide sensor output regarding fluid chemistry of a fluid of a cooling system. The controller is to identify attributes of the fluid. The injector is to inject at least one additive into the fluid to bring at least one attribute into a threshold range.

The present invention relates to a cooling loop, in particular for a motor vehicle, the loop being configured to allow a heat exchange between a cooling liquid and a liquid to be cooled. According to the invention, the cooling loop includes an on-board sensor which is positioned at least partially in contact with the cooling liquid, the sensor being configured to supply at least one datum relating to at least one physical property and/or chemical property of the cooling liquid.