Heat damage on one face only is a record of exposure, not of material quality. This entry separates radiant heat with a clear line of sight from conducted heat arriving through a fixing, and gives a bay check that tells the two apart.
A gauge that climbs when stopped and settles once moving is an airflow fault, not a coolant-side one. Fan, shroud, the stack ahead of the core, and trapped air.
A white deposit on a silicone hose is dried coolant, harmless surface bloom or road salt. Texture, position and a wipe test tell them apart before you buy anything.
Every silicone hose softens as it warms, so judge the fault by behaviour, not by feel. Reinforcement, fluid attack and a crushed end all present differently.
A falling coolant level with no puddle is either a real loss or a misreading. How trapped air, evaporating seeps, internal breaches and a tired cap each show themselves.
A sweet coolant smell with a dry floor is a weep that evaporates before it lands. Where it hides, how crust under a joint proves it, and a cold pressure check that finds it.
Water in the charge tract after rain is usually road spray driven through the core rather than rain entering the engine bay. Condensation, splash and coolant each behave differently, and the routing is usually what needs changing.
An idle that hunts only after a cold air intake is a low airflow metering fault: unmetered air from a disturbed line, or a sensor sitting in a new housing. Fuel trims at idle against cruise tell the two apart.
