My 2003 Honda Civic LX 149k miles overheated last week. I was wondering since I replaced the radiator, thermostat, water pump, timing belt and got my head gasket tested (was fine) about a month ago before it got hot (I live in Phoenix) antifreeze level was fine as well and it overheated. I don't know if the extreme heat was the problem since it was 120 degrees that day. I took it to my mechanic he was in shocked that it overheated since he replaced Everything. He drove it home, back to work and let it run for an hour it didn't over heat. He called me and told me that he wanted to do a few more test on it and he'd call me in a few hours. So he called me, he told me that it's loosing coolant, something about a cracked head gasket and combustion chamber. He said he was going to put a sealant into the radiator to fix the crack. I was wondering should I buy a engine and replace it so don't have to go through the hassle again or have him fix it by replacing the head gasket and what not? He has the car for the weekend and is going to drive it and let me know tomorrow (Monday) what is going on and how to proceed. You have any suggestions what I should do?