How to Pressure Wash an Engine

by Jenny Carver

Engines are often forgotten when it comes to cleaning and washing a car. Onlookers don't see the engine, so most people don't wash it. Most people forget about the dirt, mud and road grime that build up under the hood and on engine components. The engine and engine bay should be cleaned at least a few times a year, but should be done properly to avoid water damage. Learn how to pressure wash an engine and get your engine shining like new without damaging any parts.

Park the car in the shade so that the sun doesn't shine directly on the engine area. Use a trash bag and masking tape to cover the fuse box, battery terminals, throttle body, alternator, injectors and spark plugs. The trash bag can be cut into smaller pieces and taped over and around these parts.

Spray Simple Green on the dirty, greasy areas of the engine. Once the vulnerable parts are covered, the remaining parts can all be sprayed liberally with Simple Green. This greatly loosens grease, oil, mud and road grime. Allow the Simple Green to sit for about five minutes, but don't let it dry or it will leave a haze on the parts.

Use the pressure washer to spray off the Simple Green. A sponge may be needed on really dirty areas. Point the sprayer toward the engine bay, stand back as far away from the engine as possible and spray directly at the parts until the water runs clear (no more foam or bubbles from the Simple Green).

Remove all of the tape and trash bags from the parts. Drive the car for at least five or 10 minutes to dry most of the engine components.


  • close Don't spray the pressure washer up close to any of the engine parts. The water coming out of a pressure washer is very strong and may loosen or break some smaller components of the engine.

Items you will need

About the Author

Since 1997 Jenny Carver has served as editor and freelance writer for many offline and online publications including,, "Hoof Beat News," "Import Tuner" and others. Carver owns a custom automotive shop where she has been doing paint and body work, custom interior work and engine building for over 11 years.

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