Mercury Sable 1999 Owner's Manual page 177

Maintenance and care
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.
3.0L Vulcan engine
3.0L Duratec engine
177