Have you checked the sensor condition : IAT, IAT2, MAP, O2? At least the first 3 you can clean with maf sensor cleaner.
Fuel is used not only to power the engine, but cool it as well. Not sure this applies here, but during extended idle, if the fans do not kick in, raising fuel trims would be one way of controlling runaway temps.
It also may be something that needs a programming update to fix.
Wiil dig further.