Lately,since the summer heat is here my coolant has been boiling over into the expansion tank and out onto the ground.I have searched and have found some help but not specific to my problem.I'm thinking it is my t-statbut not sure?it seems like every day or two I have to put in more coolant because it keeps spilling out of the expansion tank.What could the problem be? I plan on doing a radiator flush soon and was thinking about changing the t-stat.Could this be the problem? any help is appreciated! thanxs