Replace your damaged intercooler and get your 2003-2004 Dodge 5.9L Diesel back up and running. The purpose of an intercooler on a turbo-diesel engine is to cool down the charge air after being compressed by the turbocharger. The intercooler cools this air before it enters the intake manifold. You can get a factory-style replacement as well as an upgraded unit that provides you with increased durability for elevated boost pressure. You'll find top manufacturers such as AFE, Banks Power, CSF, XDP, and Mishimoto to choose from.