Step 1: plan
Ideally, choose a hot day. The warmer climate, especially the low humidity with a little wind, will help to dry the engine and components after cleaning.
Step 2: let cool
If the machine was running, turn the hood over and let the engine cool for at least 15 minutes. Hot engine parts can not only burn you, but can also be damaged by a rapid contraction if sprayed with cold water.
Step 3: remove the secondary components
Remove any plastic covers under the hood. These can be washed separately. Also remove the negative terminal from the battery. This will help protect the electrical components from damage if they get wet. You can also remove the battery if you prefer, but we have cleaned many areas of the engine without doing so.
Step 4: cover
Using plastic bags, cover all sensitive electrical components, such as the battery, ignition cables and engine control unit. If there is an engine air intake exposed under the hood, cover that one too. If you feel particularly careful in rinsing, you can skip this step. However, the protection of these electronic devices will allow you to clean more thoroughly with less risk of causing damage.
Step 5: degrease
Carefully spray the entire engine compartment with the degreaser. Any domestic degreaser will work well, whether it is a kitchen cleaner or a specially designed engine degreaser. It abounds in splashes covering the entire surface.
Step 6: stain removers
Depending on how dirty your engine is, you may not need to scrub. However, some areas, such as the valve cover, may have old residues of encrusted oil and dirt. A small brush with synthetic, non-metallic bristles will contribute greatly to achieving a good final result. Add more degreaser if necessary.
Step 7: rinse
If you have an electric washer, you can use it on a clear setting, but a standard tube will also work. Or you can use the sprayer at the local DIY car wash. Rinse the entire compartment, working from back to front, washing away all the degreasers. Try not to directly spray electrical components and try to avoid spraying plenty of water in areas that will not dry easily.
Step 8: dry
If you have compressed air available, you can blow it in the corners and slits to remove excess water. If not, clean everything you can with a towel or rag. This will not only remove water, but will also help remove any remaining dirt.
Step 9: put back in place
Reinstall the negative terminal on the battery and remove the bags that cover the electrical components.
Step 10: repeat
The key to making this project simple is to let the engine compartment not get too dirty. A quick cleaning every year or two will help keep the engine clean with no more than an hour of work. As they say, better prevention than cure.