Eagle talon tsi awd problems?

lowell it heats up very quickly, so i checked the antifreeze and it was ok. and it also has no power at all when it gets even a little tiny bit over the half way mark on the engine temp. but when its cool it rockets away usually.but like i said if its even slightly over half it is a pain to go anywhere, foot to the floor and still nowhere ive herd its a blown head gasket ive also herd its the vacuum hoses and its the transmission but i rather not spend my money guessing on what it is so please help someone