Over Heating Problem

[HSV_90]

Hi all
when i go on trips and i stop i can sometimes here the radiator coolent in boil when car is off,the temp gauge sits on the first line so it doesnt say its not over heating,but when ya stop ya hear it boil,if i cruise round town the temp gauge sits in the middle,i have flushed the radiator out bout 3 times,and used new coolents,i checked the hoses they look fine,so i dunno whats happening,anyone help

[immortality]

Hi all
when i go on trips and i stop i can sometimes here the radiator coolent in boil when car is off,the temp gauge sits on the first line so it doesnt say its not over heating,but when ya stop ya hear it boil,if i cruise round town the temp gauge sits in the middle,i have flushed the radiator out bout 3 times,and used new coolents,i checked the hoses they look fine,so i dunno whats happening,anyone help

probably a dodgy radiator cap. i had the same problem for a long time, slowly loosing coolant? i was, but could never find a leak. i think what happens is that when you switch an engine off the temperature/pressure actually increases a little cause there is no circulation. this extra pressure is enough to push past the radiator cap causing pressure loss and the boiling you mentioned in the radiator.

[Not_An_Abba_Fan]

Yep as above. Is your overflow bottle filling up when you stop? then it would point to your cap. Otherwise it is quite normal to hear the coolant make noises when you stop as it does heat up and build pressure.