Esmaeil Farid

I’m facing overheating on my 2014 1500 GMC Sierra 180k kilometers (around 120k miles) with the LT engine on idle only so when the car is running temperature goes back to normal. I have tried to troubleshoot the cooling system and nothing is faulty, the coolant is flowing regularly which means water pump and thermostat are functioning good, fans are functioning as well, the coolant was changed 30k miles ago Any help? thanks esmaeil