i searched about this issue but nothing i found was like this problem.
ok i gotta a issue with my 2001 mustang 3.8l v6 again. my car just sat in my driveway the past months during winter. i happened to smell antifreeze as i walked past the car one day so i popped open the hood to see why and i noticed a puddle of antifreeze just under the thermostat & thought id check the level of coolant in the radiator and when i opened the cap it let off pressure like it had just been driving recenty and antifreeze started coming out. couple weeks later same thing and again recently. when i get the radiator full and the bleeder on top of motor topped off with coolant. i of course turn the defrost on high full heat and start the car to top it off like normal as its running i add lil coolant and when it gets to where i can see it the antifreeze level it end up overflowing and starts spitting coolant out the top and continues spilling over. i just replaced the water pump yesterday hoping it could be the issue. ive read that this could be caused by head gaskets leaking but i just had them replaced not long ago so doubt it is that. i just did a cylinder compression check all checked out good, no sign of antifreeze in oil, had no signs of bad head gaskets so now i need help and you guys here always seem to know the answer to my issues so im hoping u can help me with this issue.

what do u guys think about this? any ideas or thoughts will help. thanks sorry if i left out any key things that would be useful for u to know.

oh i replaced the thermostat also with the water pump.
almost forgot i did a cooling system pressure check and it seemed to hold pressure great needle didnt drop at all.. but also after i did the test i pushed the pressure release on the pump and only like 1 psi of air came out then just anitfreeze started coming out and pressure gauge didnt drop at all after quite a bit of antifreeze came out & it wouldnt stop everytime i tried pressing the release on the pump, i had to open the bleeder on top of motor which the pressure gauge started going down on the pressure test pump. not sure it that helps but maybe .

i was out messing around a lil more and actually topped of the radiator and started it up and the fluid dropped right away i let it run for a couple mins before i added a lil more coolant to top it off and as soon as it topped of it started to slowly start overflowing so i put the radiator cap on and let it run a bit to open the thermostat and while it was running i felt the hoses to check if they got warm or not and the lower hose never got the slightest bit hot but the upper hose started felling warm but only the first few inches from the thermostat and the radiator side was warm a few inches from the radiator but the of the hose was no where near as warm as the ends so i used the didgital ir temp reader to checks the temp at warious places and at both ends of the upper hose was about 120 degrees and the middle was only 60 degrees the bottom hose was about 60 as well i checked the radiator temp by the upper hose and it was close to the same as the hose but the rest of the radiator wasnt around the 60 degree area. radiator cap was not warm either. i checked the water pump and it was around 120 the bypass hose was hot around 120 also. the fan inside never blew out warm air at all either. the car ran for at least 10 or 15 mins til i shut it off. i dont see how the upper hose can be warm at each end but not the middle at all and the radiator only being warm where the upper hose is connected. i flushed out the radiator and the hoses and the expansion tank before i filled it so they cant be clogged. i was thinking maybe plugged in radiator somewhere but idk.

i take good care of maintanancing the car and keep up on everything and i never drive it during winter months so its a really clean vehicle and all so its not a neglect issue or anything. hopefully this info helps finding to issue.

thanks sorry for the book but just giving the most info i can.
any help would be greatly appreciated.