my gallant ran hot and cut sat over night and now it wont start. on 2006 Mitsubishi Galant

there is no water in the dip stick,although the oil is dark brown.there is a oily like substance near the bottom of the radiator.the radiator took about 3/4 gallon of water.when trying to crank the sound is low almost as if the battery is it a blown headgasket?is there a test that can tell me whats going on?it shut off on the interstate while being driven by my daughter,so i dont know how long it was driven!!!

Asked by for the 2006 Mitsubishi Galant