Argh! The squeal!
This one's really easy. The motor bearings are dry, and need a drop of oil to make the noise go away. It won't take much, just a drop on each end of the motor shaft. Let it sit a few minutes,. then put it on the track, and let it run around for a few minutes. Then, take it of the track, and put another drop of oil on each end of the shaft, and add a drop of oil to the gears, as well. Put it back together and enjoy. The Pemco engines were some of the better single-truck pancake motor powered engines. They originally were sold through Woolworth's.