Ive got a 1996 camaro rs. 3.8. If i set for a while mytemperature guage will go up to about the quarter hash mark. But anytime i am moving, it never goes above 160. THis is a problem cuz i live in a cold state and unless im sitting still my car has no heat. As soon as i start moving it goes lukewarm. WHen i park for about 10 minutes it gets warm again. I know i do need a coolant flush, but i dont think that fully explains the situation. Im also gonna replace the thermostat. Any other suggestions???

 

thermostat would be first guess if it's stayin cold its stuck open

 

Need a warmer t stat than 160 in winter, if you want to stay warm.