|This article is about a/an companion/ally who doubles as a mecha vehicle in Engine Sentai Go-Onger.|
|"Going down- Engine of Light, K-Line!"|
|―K-Line's role call[src]|
Engine K-line (炎神ケライン Enjin Kerain) is a hybrid of a Triceratops and a freight liner. He is split into two items when in storage, an Engine Cast and the number 12 Engine Soul. He serves Kyouretsu-O's left leg and Engine-O G12's left arm. He forms the last car of the Ancient Engine line.
K-line has tremendous rushing power, and is able to break through many things with his three horns. He can also jump up and bite foes in tandem with T-Line. Being of primitive origins, he cannot talk but only speak in Triceratops-like roars, which can be understood by the others.
- His title as the "Engine of Light" is a reference to the fastest generally available train run on the Tokyo/Osaka/Fukuoka line using the Japanese Rail Pass.