Replace your damaged intercooler and get your 2006-2007 Chevy/GMC 6.6L LLY/LBZ Duramax back up and running. When replacing your intercooler, you can find factory-style units as well as upgraded versions that offer increased strength to handle more pressure. 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. Mishimoto, AFE, Banks Power, CSF, and XDP are just some of the top-quality brands that are offered for your vehicle.