Thomas & Friends (1984)

S3E10 The Trouble with Mud

Gordon finds himself coated in mud, yet stubbornly declines to be washed off. In response to his defiance, the Fat Controller assigns him the task of hauling trucks while James takes charge of the Express. However, when Gordon steps in to assist James, he realizes the importance of cleanliness, concluding that "a proper wash is vital for every engine."