Bumsdeclaf

I have a 94 GT, mostly stock just Cobra intake, MSD ignition, 9mm wires, 70mm BBK TB, Shorty Headers, BBK off-road h-pipe, Cold air intake, and smog pump eliminator. Also 3.55 gears and aluminum driveshaft. the car has about 90k miles on it and the oil and filter has been recently changed. this is my story. the car has only truely overheated, as in "in the red" once because one of the radiator hoses popped. at the time i believed that nothing serious happend with the car so i just replaced the hose and it ran fine, it dident overheat again. Now almost a year afterwards its running really hot, not exactly on the red line, but getting there. at first i thought it was because of not using coolant, and just 100% water, that caused rust and the rust clogged the radiator causing poor circulation thus overheating. i flushed the radiator and now have half water and half coolant. after that the temp gauge was very erratic but that was fixed by changing the sensor. at first the car was fine, then it starts overheating again. the thing is the car overheats while running. you'd think that at higher speeds with the air passing it would cool down but it doesent. and when i stop moving and i rev it up it goes down. so im not sure what to do. is it time to upgrade the radiator and pump?

there is another possibility and i also wanted to know if any of you experience this: when the A/C is on the temp goes up, which is funny since the fan turns on automatically along with the A/C, not just when it gets hot, and my fan is fine( but it is the stock fan). this is also kinda strange: i turn on my headlights- temp goes up. press the brake- temp goes up, turn on any electronic thing from my car, even make the A/C fan blow harder, which is an electric fan completely independant from the engine and should not affect temperature, makes the car run hotter. so im starting to think that the car is'nt running hot but instead the alternator is'nt so good and not providing the temp gauge enough electricity to mark the correct temp. (because if the temp gauge has no electricity going to it it automatically falls toward the hot side, so less electricity going to it makes it turn in that direction)

Personally its driving me insane. im going to change the thermostat, but if things dont get better i dont know what to do. HELP ME PLEASE

TENGRAM

yeah if you didn't change the T-stat after the first overheat then its likely causing your problem now. they dont fair too well after overheating. dont go lower than a 180* T-stat, it can cause problems.

if the guage is in the red, the car is extremely overheating, not just a little. it shouldn't get close at all. the a/c will make it run hotter, no problem there. you may want to check that the fan is operating properly and Checking for Codes may help.

Bumsdeclaf

Thanks man, ill try that out and tell you how it turns out

Sup3r52man

It sounds to me to be electrical, my 5.0 had close to the same problem, ended up being the electrical connector for the radiator fan. Anytime I would use power for something else in the vehicle it was raise my temperture. I ended up having to strip the wires and replace the connecting harness for the radiator fan, havent had a problem with it since.