Newbie..Need Help! My g/f's Car Keeps Overheating...Why!

I also posted this thread in the civic section but it never hurts to post it somewhere else to get more heads into this discussion. This is long so please bear with me and i'd greatly appreciate it if you read it all.

Hey there guys, i'm a newbie here so please excuse my ignorance or anything. I decided to go to you guys for help because i'm at end wit with my g/f's civic and i'm sure you guys can shed some light on the situation. My ladies car is a '93 LX with the 1.5 (D15B7..i think). Ever since she's had the car, her car will overheat in moderate to high ambiant outside temp. Yesterday, i replaced her radiator because it was leaking and i thought that might be causing the problem. Well, i installed the radiator, all new hoses, new coolant, new thermostat 3 months ago, new water pump was installed 2 years ago, radiator cap is 3 months old, and i also used that nifty bleeder screw trying to get the air out of the system. I have no clue what else can be causing her overheating problem because pretty much everything is new! Today after doing all the work, she took a 45 minute drive to a local mall and as soon as she got off the freeway, the temp started climbing; while on the freeway it was doing fine. one thing i noticed was that it seems as if the fan for the radiator doesnt come on at the right time, but it does work every once in a while. She got the radiator fan switch replaced about 6 months ago along with the fan relay. Once she got home, she let the car sit for about 30 minutes and i asked her to pop the hood..when she did that, i slowly turned the radiator cap and a shit load of pressure went into the resivoir bottle. I looked into the radiator tank and i couldnt see water in there, but there was some in there because i squeezed the lower hose and some water appeared to climb the transfer tube from upper radiator tank to lower. What is going on here?!?! I'm loosing my hair over her car! Any comments or suggestions will be greatly appreciated. On a side note, i'm not one of those redneck 4x4 guys that hate "ricers", i've always appreciated what people do to imports. Thanks

Do the radiator hose's collapse? Have you checked the oil for any sign of coolant? Any white smoke from exhaust?

I'd also check the fan, and everything electrical involved with it.

Alot of overheating problems are caused by clogged hoses. Did you flush the system when you had the problems? Might need to do a good back flush to get all the crap out of the hoses.

I also had the same problem on my 92 civic. Her headgasket is probally leaking. A new one would fix the problem. No one told me and I ended up blowing it completely and spinning a bearing. Crap! I just remembered I left my bottle heater on. I'll brb.