You said you put some oil on the bearing. Did you clean it off first AND clean out the spindle well before adding new oil? It might have some schmutz in it and needs to be cleaned.
Was the belt still attached to the platter when you spun it without the motor? Take the belt off an see what happens. The noise could be coming from the motor shaft/pulley if it is turning with the belt.
Was the belt still attached to the platter when you spun it without the motor? Take the belt off an see what happens. The noise could be coming from the motor shaft/pulley if it is turning with the belt.