I also have a cooling problem. MY car (3.0L Lebaron) doesnt cool the way that it should. The temp will go to a little past the 3/4 mark then cool back down to as low as the 1/4 mark. I recently had a new water pump put in, a new radiator, and a new radiator cap and it still does this. I replaced the thermostat with a cheap 5 dollar one and a 22 dollar Chrysler one. I also replaced the engine coolant temperature sensor. I have no idea what to do next. I know that if I take it to a mechanic I will get raped. Any ideas?