03 w/ Cracked Radiator Wondering why???
 

This truck seemed to have an erratic temp sensor. Once (when it was warmed up) on the highway climbing a hill the temp gauge almost pegged. It didn't ping at all and when I eased up on the throttle it dropped back to normal. It never lost power either. So I didn't think it was as hot as it indicated.

Well recently it cracked the right side of radiator near the top. I am wondering if these motors have air bubble tendancies. Is there a way to burp it when I put it back together? I pulled the thermostat off and it seems to be ok. I took pics to post later. I'm wondering if it opened late and super hot fluid rushed into the cold radiator? On another forum I read about people drilling holes in the thermostat valve to prevent temp shock. This thermostat has a small ball cage check valve to prevent backflow and meter out hot fluid in advance of it openning. I did notice how small it is and that the spring can block it off pretty easily if rotated over it.

I don't want to blow another radiator or worse... open to suggestions.