Per Joe Strapac's 'Espee Historic Diesels Volume 5': " Disliked by many maintenance personnel due to their 'differentness', the Sulzers operated only sporadically in revenue service.( One SP locomotive plant manager told the author that he'd never seen so many oil filters on a single engine.) Maintenance of the cooling system was a time - consuming process. Radiator air was circulated by two sixty - inch cooling fans driven by hydrostatic(instead of electric) motors that received high - pressure oil from an engine - mounted oil pump."
Cooling system overheating was such an issue, despite the expanded surface area, that Espee moved the dynamic brake grids from the radiator side inlets to the roof. Also mentioned, the unit that failed on its 1st run suffered a traction motor failure.( Kinda rare if it's a GE 752.) It would seem that M - K didn't know how to mate the many different components together to Espee's satisfaction. The Sulzer engines themselves were not the biggest problem, as evidenced by their sale to a marine user after Espee retired the units.
Also remember that EMD & GE were NOT receptive to having anyone re - engine their locomotives with a ' foreign ' prime mover; supply & support for such projects was virtually non - existent.