i've been running around for 3000 miles since my engine has been built, with no thermostat. going down the road on a cool day my temps stay right around 150-160 degrees. on a hot day going down the road the temp stays around 180. but at idle all the time the temp will always make it's way back over to 210 degress. now the car never overheats, i never see coolant running into the overflow bottle. i'm just wondering is this okay? cause with my turbo timer my cars just setting there idling at 210 degrees.

All modern cars need a thermostat for street use. Besides keeping engine temperatures _up_, a thermostat serves to restrict flow of the coolant through the water jacket passages. Heat transfer relies on 3 factors: temperature difference between the hot and colder items, amount of area conducting the heat, and the _time_ the items are in contact. Without a restriction, water can flow through the engine too quickly in some areas and cavitate, leading to localized hot spots and steam pockets, which result in no cooling in those areas at all. Not the sort of situation you want near your exhaust seats. The engine was also designed to have parts at a given temperature, affecting clearances and sensor readings. Put in the factory thermostat.

your car is in warm-up mode when running temps less than 190. as a result, your ecu is dumping a ton of fuel to get the car warmed up. put it back in.