I have a 94 z28 and i have coolant leaking somewhere but cant figure it out i had a hole in the radiator and i thought that it was that but it wasnt i replaced the radiator and still seems to be leaking, i will fill it up and depending on how i drive the coolant will last like if i get on it it must **** it out or something but when it starts to over heat it gets hot then if i go let some pressure out of the radiator it goes away till it builds up again then if i put water in it its fine till it gets low again

 

make sure the radiator hoses are good around the seals where they meet the radiator (shouldve been replaced w. new rad. but u never know.) also check the stupid things like maybe a bleeder valve open, they are right by the thermostat, do you hear gargling when its hot, also is your car lacking power at all

 

its not lacking power, i replaced the radiator myself and the hoses werent replaced it, there is a gargle noise there isnt much coolant in it when i does over heat

 

Couldnt he just do a pressure test? Do you see a puddle or just everytime you check it it gets lower?