Replace the failed intercooler in your 2017-2019 Chevy/GMC 6.6L L5P Duramax and get your vehicle 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. When replacing your intercooler, you can find factory-style units as well as upgraded versions that offer increased strength to handle more pressure. You'll find top manufacturers such as AFE, Banks Power, CSF, XDP, and Mishimoto to choose from.