Originally Posted by Ubetit

Nothing wrong with water under the hood. Been using water under the hood for 15+ years. I never met a pro-detailer that didn't use water under the hood, whether steam, pressure washer or just the hose.

Here's what I do....

1.Cover any sensitive electrical components with foil.
2.Spray engine bay down with Megs APC.
3.Let it sit for 10 minutes. Scrub with soft bristle brush on caked on areas
4.Remove nozzles from hose and rinse the bay with the waterfall flow
5.I spray CD2 engine detailer (many use Armor All Tire foam) and coat the bay.
6.Close hood and start engine.

After a few minutes open the hood and wipe down any spotty areas.

Many pro-detailers do it this way or a variation on this way with different products.. Many use a pressure washer instead of the hose though.