足版，the coolant changed when i bought it from previous owner

Also checked coolant level, radiator cap and reservior level, all seems in good condition, no obviously coolant loosing. color still in blue clear transparent condition. as i am checking engine coolant temp from daily driving, this is all happend recently, coolant temp keep climbing when in stop without fans kicked in; so try to do a pre-cautious diagnose to prevent any disaster engine overheating