2003-2007 Ford 6.0 Powerstroke Diesel Engine Oil Cooler Kit with Screen & Gasket (OEM 3C3Z-6A642-CA) - Improved Cooling Performance for Heavy-Duty Trucks & Towing

Initially though I had a bad out of the box oil cooler because I had oil in my coolant after installation. Turns out, the oil cooler was fine and it was a ruptured transmission cooler inside of the radiator. Make sure to check your radiator and transmission cooler if you have oil and coolant mixing in your 6.0 powerstroke, don't assume it's the oil cooler.