Exhaust popping, could be coolant?

Hey all I replaced a blown header gasket and now I'm getting an erratic popping sound out of the exhaust. When I pulled the bolt on the end of the head of course a bunch of coolant Spilled Out, some of it might have spilled into the header. Could this popping noise because by leftover coolant? I open up the headers up and drove down the road for a while but I'm still getting this popping noise. What else could it be? Can anyone help?