Reference

The power cars of the Trans Europe Express (TEE) trains on the Ontario Northland Railway were replaced primarily due to reliability issues and the need for more robust and proven power units. The TEE trains were originally acquired from the Nederlandse Spoorwegen (Dutch Railways) and used in Ontario from 1977 until the early 1980s. However, the original power cars faced operational challenges, which led to their replacement with rebuilt FP7 diesel locomotives.

The transition to FP7s provided a more reliable and efficient means of propulsion for the trains. The TEE train cars themselves continued to operate for several years even after the power cars were replaced but were eventually retired as well. This change was part of a broader strategy to modernize the fleet and enhance service reliability on the Ontario Northland Railway.

For more details, you can refer to sources such as the CPTDB Wiki here and the Toronto Railway Historical Association here.

Here are some images related to the Ontario Northland Railway and the TEE trains: