I was looking for something to clean my intake manifold because it was pretty dingy looking and I wanted my motor to look clean when it was reinstalled. I tried some metal cleaner from metalwax.com and it worked really well. I also used it on my ceramic coated AS&M Headers and they cleaned up pretty well too. Take a look: Before After

I am posting in this forum because this is more of an engine detailing product which should be used when your parts are out of your car. This product is corrosive and you need gloves when working with it. It took me about 1 hour with a couple of the small stainless steel brushes to get it looking good.