For sale today are 6 HO scale diesel engines All are functional, some operate better than others. Two of the Union Pacifics are just a few years old, while the other two UP's are vintage (I think from the 60's or 70's}  Brand names are Tyco, Bachmann, Athern, Ahn. I know all of these were running fine a couple of years ago but I have no way to test them now, so they are sold "as is".