A Pocketful Of Motor Oil

Click and Clack discover that Crusty, their quirkiest employee, once invented a radical, zero-emission engine that burns no fuel. When the guys find a recent letter from Crusty's niece that announces her upcoming visit to her famed Harvard professor uncle, Crusty enlists the guys' help to create the illusion that he is still that person so his niece won't be disappointed. Crusty has secretly been putting her through college. How do the Tappet brothers support Crusty? And what about the engine?