Cover air intakes, air filters, oil dipstick, breather caps, distributors, coils and electronic black boxes to protect them from water spray. Use plastic bags and aluminum foil. Seal with rubber bands. Masking tape can come loose when hit with water, and plastic tape can be hard to remove when wet.
Clean the battery and its cables of corrosion with a baking soda solution and water. Be careful no corrosive battery acid is sprayed around the engine compartment or onto the body. Make sure none of the solution gets into the battery, where it can degrade the electrolyte.
Spray on engine cleaner according to instructions on the container. Start at the bottom and work upward. Since cleaners can remove wax, cover the car's body or wax the car after cleaning the engine compartment. Use a small paint brush to loosen dirt and a scraper for stubborn crud. Be careful not to damage components or wiring.
Let the degreaser sit for a few minutes to do its job. Spray the engine thoroughly with a garden hose. A high pressure spray works best. Repeat on any areas needing more thorough cleaning.
Remove the aluminum foil and plastic bags. Dry puddles and run engine until any moisture is dry.
Look for any rust or bare metal in the engine compartment. Repair rust and refinish with a paint product that can withstand high temperatures.
