You haven't mentioned the Voltage the motor runs at, however it appears to be a 6600 Volt rated Motor for which the No Load Amps of 40 appears to be about right. The temperature could be caused by shorted laminations in the Stator core as there is no load to cause any temperature rise in the Windings. The humming sound could be due to many reasons from a loose core (Stator or rotor) to unbalanced Air Gap, a wrong Winding connection, unbalanced Voltage, broken rotor bars/rings to name a few, it could also be a combination of these.