Originally Posted by CdnoilRAM
With a cool engine/bay, I bag the alternator and the intake filter (open CAI), soak the engine bay in spray-on Simple Green and let it sit for 10 min. Then I run the pressure washer on it's lowest setting, just so it's got a fan of water, rinse the entire engine bay. Once i've soaked the engine completely, I'll let it dry for 10-15 min then I douse the bay with Mother's Protectant. I wipe up the excess and then run the engine for 10 min to dry everything off.
this has been my method as well, except i found a great product for protecting...sonus trim and motor kote. non greasy, and doesnt attract dust/dirt.
i did recently read however on another detailing forum that simple green can etch/corrode aluminum...not sure how true that is, but i thought id pass it along.