I have a 2002 Century with the 3.1 engine. Last year i blew the head gasket, ripped it all apart and replaced all the gaskets, head, LIM/UIM, replaced the thermostat while i was there. A couple months ago, i started having an overheating problem, so I replaced the rad cap, then the water pump, then eventually the radiator cause it was rusted out. Still overheated. Next day, i blew the LIM gasket. I ripped it all apart again and replaced all the gaskets again. Now it'* back together and still overheating and i have no heat in the cabin, unless i rev the engine up, then the heat kicks on and the temp of the car comes back down to normal, as soon as i let go of the throttle, it overheats again and the heat goes away. Is it possible that the belt isn't tight enough, so that when i rev the engine and get the rpms up the flow is better and things work, or could it be that the stat i put in last year is gummed up. i can tell ya, when i open the bleeder screw on the stat housing, i get air and steam, then i hit the throttle and wait a sec and i get coolant out.