take it out and put it in some boiling on ur stove that is the best way to see if the spring doesnt move then its ur therm

no there is no easy way to fix it jb weld isnt going to fix it the leak is inside the intake and stop leak will fix temp and it will clog ur heater core and or cooling system not good just go buy the gasket set and fix it before u cause a bigger problem after u tear it down and u see a yellowish color on ur valve covers dont worry its just from the intake bad now if u have a milky color down by the rocker arms then its a head gasket