How do I clean this gunk!

use a scraper to get the caked on stuff off. soak it down with degreaser and let it sit for awhile. cover all the necessary parts you don't want water in. use the pressure washer. let it dry. then go to O'reillys auto parts if you have one and get the O'reillys brand cans of brake clean and finish it. that stuff will take the paint off of an engine by just squirting it out of the can. best stuff I have ever used.