overheating need help

[spooncb7]

my ls b18 is overheating, i start it up and its fine for like five minutes, it heats up and produces good heat, then two miles after that happens, the heat stops and the car overheats, the rad hoses are hard and the resivoir tank fills up, the system is bleed very well and the thermostat isnt that old and the radiator is new, kyle (h23vteclude) also told me to replace my rad cap cuz maybe it was shot, i havent done this yet cuz all the auto part stores are closed, wondering if anyone thinks there might be someting else wrong with the car, kyle dosnt think its the headgasket, i just replaced it and i still have all my power....just getting some thoughts cuz i need my car fixed asap my accord got stolen and im out ofa vehicle right now

[doitpropa]

that sux ur car got stolen ..but it could b rad cap ive never had one go but heard of ppl that have b4