[Dan12GT]

Originally Posted by 46Tbird You've got it backwards. Simple Green is about the least harsh cleaner you can buy. You can even drink it. Dawn is a fine cleaner, but it strips wax so keep it off your paint. If I were being picky, I would suggest a good car wash soap instead of the Dawn, since it has gloss enhancers for the engine plastics and it won't strip wax off your exterior paint.

Do some research simple green is harsh. Most of the application instruction suggest to dilute it. When I was younger I used it on a previous car and let it sit too long. Came back to bubbling paint. I refuse to use it ever again. Dawn is not intrusive on paint it just removes wax / sealants. It does a very good job of removing the greases in the engine bay, especially if you are running open breathers on the heads. It's also not hard to follow up after everything has dried with some detail spray / sealant spray. Also there engine bay isn't exposed to UV like the exterior paint so I don't see any reason to apply actual wax to painted surfaces in the engine bay.

Also why are you mentioning exterior paint? We are talking about the engine bay...