Nobody sees your car's engine unless they're working on it, so why bother to keep it clean?
For one thing, a clean engine is easier to work on. Even better, though, a clean engine (and the surrounding compartment) will fetch you more money when you go to sell your car or truck because it looks newer as well as better maintained. Some auto experts even say a clean engine runs cooler, according to Cars.com.
One important advantage to keeping your engine compartment clean is that it makes it easier to determine where certain parts of your car may be leaking - like a valve-cover gasket, adds Cars.com. Additionally, oil and grease cause rubber and plastic parts to deteriorate, so keeping these parts clean can save you money in the long run when those people do, to check fluids, you're not going to get as dirty as you would otherwise.
To start, disconnect and remove your battery cables first, starting with the negative cable. Brush off any corrosion the battery with a stiff brush and neutralize any battery acid with baking soda and water.
Cover all electrical parts such as the alternator, distributor and engine computer with plastic bags. Spray dirty parts with compressed air. Then clean with degreaser or all-purpose spray cleaner and an old brush. Do not use a high-pressure hose because water shooting into electrical connections can cause damage, warns Cars.com, which strongly advises against engine cleaning at the car wash or using a power spray hose at home.
Rinse and allow to dry before driving. This could take anywhere from an hour to overnight, depending on the weather.