are you sure its not the coolant expansion tank? mine crack all the time on the bottom and leak coolant. i think im on my 3rd expansion tank now..
I recently replaced the rear coolant pipe O rings, because of what appeared to be coolant burning off the exhaust behind cylinders 3 & 6. The problem is still there. I didn't pay much attention to the pipe, other than to clean the flanges and lands. Has anyone ever experienced hairline cracks in this pipe?