A thermocompression motor includes a piston dividing a cylinder into a first and a second chamber and includes a heat exchanger having at least one air channel and at least one exhaust gas channel. In a first cycle, the first and second chamber are connected via the air channel, whereby air from the first chamber is pushed into the heat exchanger and heated air is conveyed from the heat exchanger into the second chamber. In a second cycle, fuel is burned in the second chamber. In a third cycle, only the connection of the second chamber to the exhaust gas channel is open during a subsequent volume increase of the first chamber. In a fourth cycle, fresh air is sucked into the first chamber during a further volume increase of the first chamber, while the connection between the first and second chamber via the air channel is interrupted.