I've hosed and pressure sprayed (using a light nozzle) my engines for at least the last 40 years. Start the engine, spray it down to get it wet and remove leaves and other debris. Stop the engine and wipe the flat surfaces and other stuff as needed with soapy water. Start it back up and spray off the soapy water. Close the hood and let it run for 5 or 10 minutes to start the drying process. Never had a problem.
I may be mistaken, but doesn't the engine bay get water spray while driving in the rain? Rain hits the radiator, the fan(s) pull the water through and sprays it over the front of the engine and other devices in there.
2015 White/Black Limited | 3.2-L V6 | Active Drive II | Tech Grp | Lux Grp | Trailer Tow Grp | SafetyTec | Uconect 8.4AN | 9 Speakers | Tonneau Cover | Born 09-06-14 : (( (( (( (( (( (( (( :