The gauge should start to drop when the fans turn on and the coolant actually starts to cool off. Unless you are setting in very heavy traffic. That is on the Acadia, and your Traverse should act the same way. It sounds like you friends car might have an issue if the temperature stays really steady with the fans running.
Cleaning the TB should not have altered the cooling system parameters, but it would not hurt to double check the connectors around it and make sure something is not corroded or loose.
Sunday, May 6th, 2018 AT 1:19 PM