Abstract: A vehicle coolant heating system that heats engine coolant that flows through the vehicle's heater core. The heating system includes a diverter in fluid communication with the vehicle's water pump that pumps engine coolant from the engine block. The diverter is in fluid communication with an in-line electric heater that heats the coolant to a desired temperature. An outlet hose is coupled to the in-line electric heater. The heated coolant flows through the outlet hose and is supplied to the vehicle's heater core. A pump is in fluid communication with the diverter and the in-line electric heater. The pump is operated by remote control means and activates the flowing of low temperature engine coolant to the diverter, prior to the starting of the vehicle's engine. The coolant flows through the diverter and through the pump, into the in-line electric heater that instantly heats the coolant to the desired temperature.