Coolant Line To Throttle Body?

[erichamby]

2009 Aveo5

Seems to be a line that goes from the coolant res to the throttle body? What does this do? Would this being off have caused the engine to overheat?

[TurboElk]

2005 has a coolant hose to the throttle body... to Aid in warming up I believe.

[slayerized6]

It keeps the butterfly valve from freezing in cold temps.

There are people that bypass the TB with a barbed connector or just run a new line. By keeping the TB warm during cold temps, it also warms up the ambient temp of the air entering the intake, which slightly reduces power (colder air is better). The fact that you dont have it connected would not cause the engine to overheat, but if you lost coolant because it wasnt connected, then thats why your engine overheated.