What parts should I protect before I spray down the engine bay with a hose for cleaning? Or is that a big no-no? I am assuming battery and maybe the coil packs on the valve covers? I accidentally messed up my supercharger clutch bearing when I tried to clean the engine with a citrus degreaser ... cost me an arm and a leg almost. Now I'm paranoid about what parts I need to watch out for, and was curious to know your experiences with hosing down the bay.