I have a 90' formula with a 305tbi 5speed - and its overheating. My air deflector is in place, i have a 160 thermostat but for some reason it is still overheating- the strange thing is that it only does it every other day or so. On the highway i have no trouble but in regular trafic it runs at about 250 or so- My fan is turning on- i can't seem to figure it out- anyone have any ideas?

 

i have a jet fan switch that i am planing on putting in- it will turn the fan on at 200 and off at 180. Also i have added wetter waterl, and it only runs about 5-10 deg cooler

 

I have the jet switch and it works wonders for my heating up.