Riello Burner Motor Sound?

Getting an wineing sound when the motor comes on after the normal programed delay. Almost sounds like the pump is starving but the sound it is on the right side of the motor away from the pump. It was a minor intermitent sound 2 months ago which now has become a screech at times and others times not even there. The service guy took off the cover where the fan is but since it is a sealed bearing could not lubricate. He has never seen this problem on the Riello burner before but is going to replace the motor to see if that sovles the problem. I replaced the Becket burner with the Riello about 6+ years ago and was contemplating going back to Becket. No other problems other than a leaky pump but that was out of warrenty. The service guy said stick with the Riello unit it is superior to to the Becket. Anyone else experienced this problem?