A coating for spark plugs and engine parts is resistant to fouling. The coating may be applied to the spark plug or engine part by dipping the part in a sol gel solution, ensuring it wets the part, and extracting it at a slow, controlled rate. As the part is allowed to dry, the sol gel reacts with moisture in the air to form a thin oxide film. Unlike conventional sol gel applications, which apply the oxide directly to the part, the present invention may form an oxide coating, in situ, while drying in place on the part.