Ok... I recently had my radiator tank fixed, because it was cracked after hitting a hard dip... I got it out of the shop, and it was still getting hot. I found out that the problem was that the fuse to the cooling fans had blown out. I replaced the fuse and the fans are working again. Then the car began to overheat again. I was told that the problem was the thermostat. I replaced the thermostat and refilled the radiator, and the car was running great and at normal temperatures. Today, the car didn't overheat, because I didn't allow it to, but the coolant was boiling and pouring out of the overflow tube at about 220 degrees. I checked the cap to the radiator tank, and it was bent up, so I purchased a new one, but I don't know if it is sealing all of the way. Could this be a problem, and is there a cheap way to check if thats the problem? I've already had the car pressurized for leaks, and there were none visible. The only time I see leaks is when the coolant gets to hot and pours out of the overflow. I think that there may be something wrong with the top of the coolant tank reservoir, because its hard to twist the cap on, and even harder to get it off. Please help! I replaced the thermostat myself, and I installed it exactly the way I took it out, so I know that I didn't install it the wrong way, but could there be something wrong with it like it not opening up or anything? I purchased it brand new from CarQuest.