Took car to the local off-road park and got muddy water everywhere in the engine bay

[Wild_Bill_Kelso]

For your (otherwise clean) engine.

Don't use armor-all... after a while it will turn your black hoses... er... grey.

Armor-all has silicone which in extreme cases, can trip up a sensor. Use Aerospace 303 under the hood

 

[STLDAVE]

Maybe the different grade of aluminum in the aircraft? I've been using Simple Green for years on different road vehicles and haven't had issues. I even spray it into the radiator and AC condenser.

From the Simple Green website's FAQs.

 

[dade73]

connect a sprinkler to a garden hose. though it underneath and let it go. every 30 mins or so move it around.

 

[Whippersnapper02]

From the Simple Green website's FAQs.

Thought so. Literally never seen it stain anything unless maybe you never wash it off.

 

[Pastor passum]

From the Simple Green website's FAQs.

When I read cautions like that I generally don’t use the product. Some will read that and feel that it’s perfectly OK to use. I get from it that it does corrode aluminum and the longer you leave it not totally rinsed, the more corroding it’s going to do. But that’s just me.

 

[phillyd2]

Been using Simply Green and a Hose since 2006 on two 4Runners great results and without drama.

But I would wait till it got dirty instead of the dust shown in the OP’s picture.

 

[williamson36]

Please don't use a pressure washer - there is a much higher likelihood of forcing water where it doesn't belong!