Don't just cover up the oxidation with new covers and crap. Take the time (lots of it) and scrub, polish, protect as much as you can. The longer you leave it the harder to remove. If it starts to pit then forget about it ever looking new. Lots and lots of elbow grease. You can do it, just be patient and methodical. Look up threads on how to clean an engine compartment. You don't have to cover up much and you just use a regular hose (no high pressure). Yes you can pour water over most of your engine compartment. Look it up.