Abstract: The engine block warming controller is an engine warming device for diesel engines. The controller includes a thermostat/temperature controller unit that monitors temperature outside during operation of the engine block warming controller. The unit includes a sensing probe for sensing the outside temperature. A heavy-duty outdoor timer controls time to turn on and off the engine block warming controller and a heavy-duty extension cord electrically connects the engine block warming controller to an engine cord of the vehicle. A backing board is used for securely receiving the engine block warming controller to mount it on an inside wall away from outside elements. A plurality of fasteners mounts the probe on an outside wall to detect a temperature of the outside elements. When the timer turns on the controller, the probe detects the outside temperature and warms the diesel engine.