Eh, to toss in another opinion - always have washed the engine cold. Been pleasantly surprised with the use of tire Bleche-Wite, somewhat disappointed with engine degreaser in that it removes the grease but leaves the dirt. Hose everything down, then use compressed air to chase the puddles of water. Let air dry for a couple of hours, then fire it up with the hood open and let heat to operating temperatures to chase the rest of the moisture off.