1. A method for managing a power train of a motor vehicle, which is provided with an engine and an estimator of a temperature at a specific location of the engine, comprising: initializing the estimator when the power train starts, the initializing comprising: determining a stop time of an element of the power train, determining a temperature of ambient air when the stop time begins, determining at least one temperature of the engine when the stop time begins, determining a temperature of the ambient air when the stop time ends, evaluating a thermal parameter of the engine in accordance with the stop time determined, the temperature of the ambient air when the stop time begins, the temperature of the engine when the stop time begins, and the temperature of the ambient air when the stop time ends, and initializing the estimator based on the thermal parameter evaluated; estimating the temperature of the specific location of the engine using the initialized estimator; and controlling a cooling circuit of the motor vehicle to limit cooling of the specific location of the engine when the estimated temperature of the specific location is below a predetermined threshold or for a predetermined period of time.