You can clean a care engine with steam, or you can clean it with hot water. If it isn’t too dirty, you can even just use a rag. Get a degreaser at the auto supply store. Cover up any electrical parts with some tin foil if you want to use the water. Spray on the degreaser and let it sit for a few minutes. Either wipe it off with a cloth, spray at the car wash with water or use a steam cleaner. Repeat as needed.