It started over heating yesterday... didn't notice any le...

Hi and welcome to JustAnswer! You can ask unlimited questions to any of the 12,000 Experts! From doctors, lawyers, tech support, contractors, tutors, auto and boat mechanics, appliance technicians, veterinarians, accountants, appraisers, psychologists, engineers, heavy machinery masters, dream interpreters, and more, we've got you covered, 24/7. My name is \*\*\*\*\* \*\*\*\*\* I will be able to assist you. I’m sorry that you’re having trouble with your vehicle. Don’t worry though, we’ll be able to figure this out. Thank you for taking the time to let us help you out with this problem and hopefully we can sort it out quickly. Please understand that I do not know your knowledge or capabilities so I may need to ask questions to find out basic information to help solve your specific problem. Sometimes it may take a moment for me to respond because I may have to look up information about your concern. I appreciate your patience and will provide responses as soon as possible. The heater core will not blow hot air if the coolant is low. If you saw antifreeze next to the firewall then the heater core may be leaking. It will drain out of the evaporator drain if it's leaking. You'll need to use a pressure tester to pressurize the system and see where specifically it's leaking from. You can rent these from most auto part stores if you don't have one. It will squirt out so you can easily see which hose is leaking or where the coolant is coming out of. My goal is to give you the best service possible and to help you. If you have any questions or concerns, please don’t hesitate to let me know. If I’m not online at the time, I will respond ASAP when I get back.

I don't need a pressure tester you can actively see the leak without the car even running. Yesterday when I noticed it over heating I turn the heat on high obviously to cool the [engine](/topics-engine-ford/) and the air was hot. Today when I did the same it was cold

Ok then if you can see the location of the leak, where is it coming from?

back near the firewall

Do you have a picture of the leak location? If you saw antifreeze next to the firewall then the heater core may be leaking.