Your thermostat is probably stuck preventing the flow of coolant to the radiator. This is an inexpensive fix.
check for clogged fuel filter,or bad fuel pump
Check the fan control
i found that in mine, it was the egr actuator
something is loose
No, it wouldn't affect the idle unless you were somehow overheating the engine.
As the vehicle sits idling the driveshaft is not rotating.
If overheating while moving it could be brakes dragging or emergency brake on or bad bearings in wheel. If overheats when idling could be bad timing, seized alternator or idler pulley bearings.
Because - if an engine (powered by fossil fuels) is running - even at idling speed, it's still producing waste gasses - which polute the atmosphere !
Well, in a round about way, maybe. If the timing is that far off, and the motor is struggling to pull the load, maybe. But just running, or idling, no way.
Possibly your radiator is not big enough. Or that radiator could have internal clog witch results in only us in half of the radiator. Or your fan is not pulling enough air though it
Low coolant? Cooling fan not working? Water pump not circulating water? System airbound? Radiator plugged or restricted? Thermostat not fully opening?
Check your cooling fans. There are two. If even one is busted, or so much as running at less than full capacity you will not be able to idle indefinitely.