My 98 civic temp guage gets cooler everytime I run the ac and gets to operating temp when i dnt..sumtimes when its cold outside it does not reach operating temp..and doesnt go to the half way mark sometimes (not reaching its operating temp) is it the thermostat? lol im 2 lazy to look into it (hot outside - )

 

Thermostat stuck open is really the only reason the engine will overcool. You should fix that though because overcooling is not doing your engine or your gas mileage any favors.

 

thank you mk378 ill get to it 2morrow..