Mine tends to idle high for a bit after startup, the fan is pretty loud for the first minute or so too. Even in 90 degree weather your engine still isn't at normal operating temperature right away. The idle should go back down after the engine comes up to normal operating temp.

Jadman: I'm pretty sure all modern vehicles have knock sensors so it should throw a code if it was knocking, I can't guarantee that since I'm not a mechanic but that would be my guess as well.

 

I would hope that it would flash a light at me. I am really hoping that it is a leaky header.
Does anybody know of any tricksto find a leak in the headers?

 

nevermind, i didn;t read your post well