1996 Ford Explorer Owner's Manual - Page 339

Servicing Your Explorer Cleaning the Engine A clean engine is more efficient because a buildup of grease and dirt acts as an insulator, keeping the engine warmer than usual. s Extreme care must be used if a power washer is used to clean the engine. The high pressure fluid could penetrate sealed parts and assemblies causing damage or malfunctions. s In order to avoid possible cracking of the engine block or fuel injection pump, do not spray a hot engine or injection pump with cold water. s The alternator, coils and air intake must be covered. Covering these components will help prevent water damage. s Never wash or rinse the engine while it is running. Water getting into the engine may cause internal damage. Filling the Fuel Tank Fuel filler door 339