Does anyone have a suggestion on how to get two Marklin engines to run? They were new in the box four years ago and only ran for a few minutes each after I got them. I am now ready to start a layout. I tested each of them but only one made a motion to run (for 1/8"). The track was getting power of course. Chances are the oil is congealed but I'm not sure I'll be able to put everything back together again if I take them apart (I know I can do that without any problem.
For your engines, try this link: www.zscale.org/articles/revival.html (I also answered, rather shortly due to pressing enter, in the chat window)
That page has a lot of info about reviving Marklin locomotives, including detailed step by step and pictures on how to deal with congealed oil for all main types of Marklin locomotive.