i have a 03 mustang gt and it has been overheating and coming out the top of the coolent tank . i have replaced the thermostat , waterpump and had a coolent flush . it ran fine for a week after that but the other day overheaded again . and it only does it when im driving in the city . i put more coolent in it and checked it a day after and it was all gone but i dont see no leaks . when i turn off my car there is always a pressure sound coming from the coolent lid . so . but the lid looks fine . and my fans are working . do you think it might be the radiator ? any thoughts

 

Get the radiator flow tested, it is likely clogged and cannot shed heat fast enough at lower vehicle speeds.

Your 2003 has "fans"

 

replace the coolant bottle cap. if it wont hold pressure it will cause you to overheat

 

That. Plus, you are in Texas and it's hotter than hell right now. My 96 was getting plenty warm yesterday

 

Your radiator is probably the culprit if you replaced all those
parts and it still overheats.
Your radiator is more than likely clogged/corroded and needs
to be replaced.

 

do the world a favor.....go find the nearest tree, and climb it with your neck