Engine Cooling problem
2003 Infiniti G35 6 cyl Two Wheel Drive Automatic 160,00 miles

My car started intermittently overheating. On three occassions now, the temperature gauge has gone up to within a few tick marks of the first heavy hot line. (half way from center, to almost touching).

I do not see exhaust in the coolent resorvoir

I do not see white smoke from the tail pipe

Keeping the car in motion keeps it cool where it is supposed to be.

When the temp gauge goes up, the AC blows warm air

When I see the gauge go up, I turn off the car for a few moments, then the next time I start it, it is working fine.

This occurs when the outside temperature gauge in the car reads 92 or hotter.

When engine temperature gauge is showing the correct temperature, the AC is cooling great and the AC fans are blowing hard

When the engine temperature gauge is showing hot, and the AC is blowing warm or hot air, then the AC fans are running slower.

There is no apparent loss of coolant

I do notice an extremely faint smell sometimes of hot coolant, but it is so faint, I am not sure of it. I do not see any measurable loss from the coolant resorvoir or any leak marks on the engine or in the exhaust.

Special note: my ac is on automatic because the control panel is damaged and needs to be replaced. As a consequence the control buttons do not work. (they want 2900 dollars to replace that control panel)