Quote Originally Posted by Init2winit
That valve is white because of the exhaust leak. No need in replacing it unless it burnt, which may be possible if you had a leak long enough. Just pull the valve out of the head and inspect the seat and valve surface. Most likely, you can just put the head back on and roll with it.
Hope so, I drove it leaking maybe 2 months. With as warm as the weather has been I didn't figure it would burn.