High-pressure washing of an engine should only be done by someone who has the knowledge. In Ohio you may have self-serve car wash bays, with the spray wand & hose, that have special settings for engine cleaning.
A selector lets you choose an engine degreaser that sprays at a safe low pressure, and then a low-pressure rinse. If there's no low-pressure rinse option, then hold the spray wand about 5 feet from the engine. Avoid spraying directly on the hot exhaust manifold. Then close the hood and wash the car exterior, to remove any degreaser overspray & splash that could damage the paint.
Among engine compartment components that are susceptible to damage from high-pressure water or steam are the alternator, electric radiator fan, idler pulley bearings for the serpentine drive belt, air filter if water is forced up the air intake housing, fuse boxes (when mounted in the engine compartment), dipsticks for engine oil & transmission fluid, wire loom connectors at the firewall and elsewhere, and battery.
Engine compartment cleaning is mostly cosmetic and normally does not impart any functional advantages to the car's operation. Exceptions are when oil or coolant leaks allow heavy gunk to develop over time, sometimes even becoming a fire hazard, and when an oil leak causes smoke & odors as the engine heats. A clean (but not necessarily spotlessly shiny) engine also makes it easier to detect & trace leaks when they first occur.