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 a hot engine with cold water to avoid cracking the engine block or other engine components.
• Spray Motorcraft Engine Shampoo and Degreaser (ZC-20) on all parts that require cleaning and pressure rinse clean. In Canada, use Motorcraft Engine Shampoo (CXC-66-A).
• Never wash or rinse the engine while it is hot or running; water in the running engine may cause internal damage.
• Never wash or rinse any ignition coil, spark plug wire or spark plug well, or the area in and around these locations.
• Cover the highlighted areas to prevent water damage when cleaning the engine.