radiator coolant...dont know, help plz

my raidator coolant tank won't hold coolant/water. I've changed ita out allrady because the old one had a crack, but not at the bottom. The new one doesn't hold water either. I'm thinking theres somehing else wrong which is making the engine work harder causing the radiator to need more water. Any ideas or suggestions plz help. (Also the check engine light comes on everytime i hit high third or low fourth.)


(P.S.
Yall have been pretty knowledgeable and hit the nail right on the head concerning my other questions, so thank you. Because obviously i know jack. lol )