Stuff you will need:
Hose with sprayer
Citrus degreaser
Spray bottle for the degreaser
Tire brush
Plastic bag
Leaf blower or air compressor (optional)
Rags

Let’s get started:
Start by washing your car, and waxing it. I use Armor All car wash stuff that washes and waxes in the same step. The wax will help protect the paint from the degreaser that you will be using. With the engine warm, but hot, park the car where you won’t mind the ground getting a bit dirty. This might leave oil stains on your driveway. Open the hood. Locate the distributor. Cover it with a plastic bag. Locate the alternator, and cover it with a plastic bag as well.
Spray the whole engine compartment with water. Do not spray the engine with high pressure!!!! Use a regular garden hose type sprayer. Using a high pressure spray can cause damage. Also spray on the underside of the hood. Also wet the fenders and areas of the car body around the engine compartment to help protect them from any degreaser they might get hit with.
With a spray bottle full of citrus degreaser, spray the underside of the hood, and all around the engine compartment. I used ZEP Heavy Duty Citrus Degreaser that I bought at Home Depot in a gallon sized bottle. It works great. Try to get the citrus degreaser on all surfaces, especially where the dirt and grease are the heaviest. After the whole engine compartment is sprayed with the degreaser, using a brush with long nylon bristles to scrub everything. I use a tire brush. Start with the underside of the hood, and work your way down. You don’t need to scrub hard as the degreaser will soften up the grease and dirt.
When you have scrubbed every surfaces you can reach, use the water hose again to spray everything. Start with the underside of the hood and work down. If there are still greasy spots, spray them again with degreaser, and scrub some more, followed by another rinse. Make sure you rinse off any painted surfaces such as the fenders that might have gotten degreaser on them.
Remove the bags from the distributor and alternator. Use a leaf blower or an air compressor to blow the water, and dry your engine compartment.
Now start your car, and let it run for a bit. The heat will help dry the engine. You can also use a rag to dry the wet spots. With the car off, you can use a damp rag to clean up the distributor and alternator. This is good to do before a tune up or other engine work because it is much nicer to work on a clean engine. And it you are doing a tune up, you will probably be replacing the cap and maybe the wires with new ones anyway. They even make stuff to spray in your engine, to make everything shiny and new looking. One such product is Meguiar’s Engine Dressing. I didn’t do this though.
That’s it. Enjoy your clean engine compartment!

Engine Before Cleaning
Engine Before Cleaning

 

Engine After Cleaning

Engine After Cleaning

 

Wife's car before engine cleaning

Wife's car before engine cleaning


 

Wife's car after engine cleaning

Wife's car after engine cleaning