LS overheats during idle

[DaPlaya]

After about 10-15 mins of driving, after idleing for a few minutes, my temperature guage races to H (hot) and stays there. As soon as i start driving i returns to the normal position (just below halfway). I had my radiator and thermostat replaced about 3 months back. Thing is, all this started happening since I unscrewed the radiator cap and checked the water. Someone told me that this shouldnt be done when the car is hot and that the car is overheating because i didnt "bleed" it. Can some one please explain...

[wynode]

Sounds more like it could be the thermo fan not kicking in.

[SKREMN]

Yeah i think its the fan
watch the car when on idle and see if the fan cuts in
if it doesnt theres your problem

[FR33K]

sounds like its your thermostat switch like everyone says (ive had to change mine before as well)

[ACTI0NMAN-1]

have you bled your coolant system to make sure there are no air bubbles? There may be air pockets where the coolant isnt reaching.

[LS Integra]

u took off the radiator cap when the car was overheated?? doesnt that like crack the head? :S