hi all. i have a 2005 forenza 4L 2.0 auto 2wd 101k. i was at a stoplight when i noticed the temp gauge rising the light turned and i got on the freeway(probably should have turned the car off but i drove home anyway). the temp immediately cooled back to to normal so assumed i had airflow problems. i began diagnosing the problem by testing the fans manually via 12v jumper wires directly to the fan motors. the larger fan spun but the smaller one was bad. i replaced it and started it up. i assumed the smaller fan was for ac and the larger for radiator. the larger fan never seems to come on so i assumed there was a problem and replaced the coolant temp sensor. i still have not seen the larger fan come on(not sure when it should) but the smaller one cycles with the ac and comes on at mid temp with the ac off. the problem now is that the overflow bottle is boiling over at mid temp(according to the gauge) right before or right as the smaller fan is coming on. i need help figuring out what to do next. im thinking possible thermostat failure, bad water pump, clogged radiator or blown head gasket(i see no mikyness in oil nor white smoke in exhaust). i have been driving the car and have been adding water as it boils over just to get me to and from work. since then i have had misfiring (code p0300) i have a limited budget but i am pretty good with a wrench. any help would be appreciated.