95 Jeep Grand Cherokee. I hit a deer and it put a crack in the radiator. I sipohoned out all the antifreeze from the radiator by inserting a hose through the cap and sticking it in until it hit the bottom. I used some JB weld and patched the crack in the radiator, then put in one gallon of new antifreeze and about half a gallon of water back into the radiator. It was full. Now shortly after I start it, I can hear something that sounds likes someone snapping their fingers for 5-10 seconds behind the glove box. I realize that this is where the heater core is located. What do I need to do to make this sound go away?