Mishimoto 03-07 Dodge Ram 5.9L Cummins Replacement Oil CoolerOil is the lifeblood of an engine, and in a hardworking diesel engine like the 2003 2007 Dodge RAM 5. 9L Cummins, keeping that oil cool is essential to the engine's health. A clogged or leaking oil cooler can reduce the oil's ability to transfer heat to the coolant, causing thinning and a loss of protection for critical engine components. Mishimoto proudly offers a stock style replacement oil cooler with new seals. This replacement cooler will restore