What? I really doubt there is any appreciable coolant flow from the heating/cooling of the coolant alone in the system. there is way too much restriction from the radiator and water pump.

 

Liquids don't expand nearly as much as gases do. This means the difference in density of a liquid will not vary as much as the difference in density of a gas with temperature. The convection currents (when compared with those in a gas) are severely reduced because of this (as well as the fact that the molecular mass of a liquid is much much higher than that of a gas). Basically it is going to move very very slowly, if at all because of the geometry of the passages it needs to flow through. Also, compared to molecules of a gas the molecules of a liquid are close together and heat more easily transfers between molecules. This further reduces any convection current because as the different temperature liquids mix conduction also occurs and the system moves toward steady state conditions (more readily than a gas). Some coolant may be moving a little in the system, but for all intents and purposes the coolant/water is going to be stagnating in the system when you shut the car off.

 

Im just gonna take the car in Saturday to a local shop and they are going to do a cooling system check. The like now has NO issue making it to the second line, and after a hard quarter mile sprint the gauge was creeping up even though I was still driving around. The oil temp hit 250 too for the first time since i've owned the car. It does smell hot under the hood, I cant tell if its a coolant smell or what, but its got an off smell. When I saw he gauge creep after the quarter mile, I set my heater control to HI and it still came out cool. Does the car not actually go to heater due to the ambient temps being around 100? I ask because at the end of winter, the heater wouldnt produce warm air at idle. Unless the car was being revved or at crusing speed, it didnt work. Ideas?