Although car is running good these days (knock on wood!), I just noticed a hairline crack in my exhaust manifold above the intake just yesterday. Also, the usual "hot spot" between the intake and exhaust appears to be getting hot again. Have not noticed any real sounds from the leak or performance issues just yet. I'm thinking of trying to temporarily repair the crack with some type of high temperature exhaust cement, not JB Weld (apparently, that doesn't take the heat too well), and see how long that works before I take it off and take it somewhere to get repaired.
I'm attaching a photo that show the crack...any thoughts, ideas, experiences with this?
(http://i947.photobucket.com/albums/ad320/racertb/Car%20Stuff/20151101_094301_zpsab1mpy1o.jpg) (http://s947.photobucket.com/user/racertb/media/Car%20Stuff/20151101_094301_zpsab1mpy1o.jpg.html)
First off, I don't know what products are available to repair this, but I would get fixed sooner rather than later. Logic is the heat/cool cycles will increase the crack. I also wouldn't expect any operating issues, as this is the exhaust manifold.
I highly recommend you do what they do for cracks in aircraft like this. Clean the end of the crack and get a magnifying glass and find where the crack ends. Then take a drill with a 1/8" bit ,or 1/16" if you can manage it,and drill a hole at the end of the crack. This will stop the crack from going any further while you find some one to weld it shut for you. They actually do this on propellors. But they don't weld the prop cracks.