That hood, where does water run off to?
Water gets into the engine bay at times… but thats not a bad thing. People have the misconception that its bad.. but it isnt.
All of the electrical components under the hood of any modern car are all weatherized (AKA; designed to be protected from exposed environmental factors) like changes in temperature, moisture, humidity, etc. and that includes rain and splash water. Obviously, you don't want to submerge any electrical components, but i regularly power wash my engine bay with water to keep it clean, and I have done that with all my vehicles since the late 90’s.
The “myth” about keeping your engine bay “dry” died with carburetors and distributor caps/rotors. In the old days, yes, getting water in your distributor cap could cause misfires or a no-start condition.
However, modern electronic ignition and ECU control does not have these issues.
As long as everything is in good working order under your hood, nothing bad would happen by pressure washing it out, and in over 26 years of doing that; I have never had a single issue.
The advantage of the
vents in the hood is heat exhaustion from the engine bay.
The air passing over the
vents is a lower psi simply based on the speed at which that air is flowing (exp, @55mph), and the air in the engine bay is traveling much slower and its hotter from the engine heat.
The low psi air is the colder/faster moving air going over the hood, and the high psi air is the hot/slow air in the engine bay. This convergence of the low and high psi air volumes creates a vacuum effect, sucking the hot air out of the engine bay, through those
vents, and therefore pulling into the engine bay cooler air from near the ground.
A cooler engine bay is always better, add on top of that the well know dependance that Korean cars fuel maps have on air temperature, that all = safer for the engine and more HP.
Disclaimer: you never want to submerge your engines’ air intake in water, either, obviously…