heater core question

the other day my 97 2.4 GA over heated and i thought the heater hoses blew. upon further inspection it appears what looks like an extension from the coil return and supply blew off. does the coil return and supply go directly in the heater hoses or is there another piece between the two? reason i ask is when the hoses came off each had an 1 1/2 long nipple attached to them that was covered by a black plastic cover. never seen this before. any ideas?

if it is at the lower part of the firewall, it sounds like a heater core. These are bad enough to get to, but thats not your worst problem. These cars are terrible to bleed the air off. The best way is to park on an incline, with the resivor being the highest point. Take the cap off, fill it up, start the motor, and let her run for about an hour. You will see it burp, fart, and belch. Add coolant as needed. Good Luck