Here's how you can clean up a greasy engine bay like this in about 20 minutes and have something beautiful to look at and help sell your car for more money.
First we get rid of these leaves in the cowl with the air blaster.
If you have any aftermarket electrical equipment or an exposed air filter, you're going to want to drape it with a rag.
Be certain to run your engine for the entire job. Wet it down lightly. Now spray degreaser everywhere. This is our Eazy Degreaser product: it's very strong stuff. I cut it 4 parts water to 1 part concentrate. Let the degreaser dwell for about minute before you get to scrubbing.
Use the brushes to push degreaser into every crevice. Rinse thoroughly and re-apply degreaser where it is needed.
Soak all rubber and plastic parts in water-based dressing. This is our Eazy Dressing product, it does a great job of making old, dried out plastic and rubber black again. Be very liberal about the amount of dressing you apply. Close the hood and let the car run for another 10 minutes.