want to ask abit

mileage: 120k

aircond: 1 year ago already major service (change condenser, flush system, clean dirt, etc)

month ago, when driving during this super hot weather, engine overheat (two bars left before full) and aircond become hot.

turn off aircond, drive slowly and temp started going down. after that, didnt happen again until recently with same condition (super hot weather, aircond at 2).

went to workshop, he said radiator karat inside. need to change (original denso RM580). i ask about radiator fan, he said its fine.

1. betul or scammed?
2. rm580 for denso radiator is okay?