Keeping your performance or show car engine clean is important to most of us. We don't want to put our car's performance at risk, however. Some swear by "pressure-washing", using home high-pressure sprayers or those found in self-serve car washes so popular in our area. The problem with this is that the high pressure jets often force water past rubber seals and weather stripping...into places it isn't supposed to go.
Our hood is put there to prevent moisture, road debris and contaminants from causing malfunctions with sensors, wiring harnesses, sending units and other electrical parts and components. Excessive moisture can cause short-outs and those troublesome intermittent problems. You're far better off using a degreaser and your standard garden hose to get your engine sparkling again. Do yourself and your engine this small favor.