I found this on the web.
Subject: [uuc] Re: awesome engine bay appearance
Ok, not everyone will agree with this, but I have been doing it for 15+
without any negative side effects, except for the current Z3 coupe only
because I have gotten lazy with age :-), but it's day is coming soon....but
before you jump to conclusions hear the whole thing out:
Clean excess grease and dirt from engine bay using automotive degreaser, and
a soft scrub brush where needed; the cleaner, the better. Do not bother to
wash rest of car yet. Rinse off engine bay cleaner and crank up engine to
dry. Buy the big economy size jug of Armor-All and a spray bottle. After
engine bay is thoroughly dry, spray down entire engine bay excessively with
Armor-All. The reason we didn't finish washing the car before is because if
there is any breeze the Armor-All will get on the fender paint and
windshield; not to fret, we will clean it all off later. You may want to put
something under the car first if dripping Armor-All onto the ground is an
issue. Once everything is dripping in Armor-All, allow to sit overnight to
soak in; it is OK to drive car during this process, IMO the heat helps, but
externally it will look messy. Next day, take a garden hose with spray
nozzle and blast-rinse engine bay to remove any excess Armor-All. Fill wash
bucket with preferred car soap and wash car. Empty wash bucket, then repeat
wash cycle. My experience is this will remove any excessive Armor-All from
areas outside engine bay. Dry car to prevent water spots in usual manner.
Then take old rags and dry/wipe engine bay down as well as possible, then
take for a drive to heat everything up good for final drying.
End result is the most awesome F*ing engine bay appearance you will ever
Repeat every 4 - 6 months as required. The blast-rinse removes excessive
Armorall enough to prevent dirt/dust build-up , but it's an engine bay so
eventually it will get dirty if you drive daily on the street. Also, I
realize there will be concern about getting Armor-All on drive belt and
pulley surfaces, but again I have never seen an issue from it using the
procedure as described, nor have I ever experienced any engine bay paint
issues. The only negative, and a minor one, is for a couple of days the
Armor-All on the hot engine/exhaust will have a unique, but not disturbing,
odor, but will soon disappear.
There will be nay-sayers (OK Brett, let me have it :-), afterall this *is*
the Internet, but it's easier to discount something rather than try it
first... so try it and be amazed.