Coolant Problem!!!!

[Zero4488]

Alright...I started my car at my friends house and drove it home....when I got home my car was smoking....I thought I blew a hose or something....but it turns out my overflow tank was boiling....my friend told me to check my radiator hose...the upper one has no pressure....thermostat maybe?....but heres the twist...my car isn't over heating while I'm driving it or when it's running...but a few seconds after I turn it off it starts to boil....Anyone got any ideas....I'm open for opinions.....

[camaro2you]

air in the system is my guess.

[JSPERFORMANCE]

could be a bad pressure cap

[jola]

does it boil when you open the cap? i'm guessing yes b/c the overflow tank is opaque and you would have to open to see the coolant. is it just pressure difference when you open the cap that causes it to boil?

where in woodbridge are you?

[Zero4488]

It boils with the cap on...I can hear it....

[deadtrend1]

how about the ratio between water and antifreeze.... just a thought