Ford 1999 Wagon-Econoline Owner's Manual page 185

Cleaning the wheels
Wash with the same detergent as the body of your vehicle. Do not use
acid-based or alcohol-based wheel cleaners, steel wool, fuel or strong
detergents. Never use abrasives that will damage the finish of special
wheel surfaces. Use a tar remover to remove grease and tar.
Cleaning the engine
Engines are more efficient when they are clean because grease and dirt
buildup keep the engine warmer than normal. When washing:
• Take care when using a power washer to clean the engine. The high
pressure fluid could penetrate the sealed parts and cause damage.
• Do not spray with cold water to avoid cracking the engine block or
other engine components.
• Cover the highlighted areas to prevent water damage when cleaning
the engine.
• Never wash or rinse the engine while it is running; water in the
running engine may cause internal damage.
Maintenance and care
185