My 2004 Kia Optima won't start

What is your question?

my 2004 Kia Optima was over heating (never got the the red zone on thermostate), but still had coolant,and the checked the hoses too. Also the later that same day my alternator belt brok so my car wouldnt start and the alternator belt was replaced. after replacing the belt car won't start and now is making a bit of a knocking sound that it was not making when the belt broke and I was tring to start the car before. Is there a saftey switch in these cars either for overheating or somthing that could have happened when the belt broke or was changed that could cause this problem