Engine runaway is every diesel owner’s nightmare


I recently witnessed a delivery truck on the side of the highway spewing flames out of its exhaust. It was riveting, yet terrifying, and it reminded me of the rare and frightening phenomenon that is diesel engine runaway. And so off to YouTube I went to watch engine after engine fail in a black cloud of smoke, as bystanders helplessly watched. So what exactly is it about diesel engines that let them run on uncontrollably?

This is a companion discussion topic for the original entry at https://www.hagerty.com/articles-videos/articles/2018/11/26/diesel-engine-runaway-nightmare


Diesels can also “run away” on engine oil if there’s a problem with the breather or pcv system.