The 6.7-liter inline-six diesel engine replaced the 5.9-liter in Ram’s Heavy Duty trucks midway through the 2007 model year. Being the first Cummins engine with a variable geometry turbocharger, it featured integrated exhaust braking and less turbo lag. The 6.7 L Cummins turbo also allowed Ram to keep up with the competition and meet 2010 emissions standards early. +Read more
However, the Cummins 6.7 L turbo diesel was plagued with issues. Because the exhaust gas recirculation system delivered dirty air back into the turbo’s intake, the VGT’s vanes would clog and fail to open and close properly, resulting in power loss. Inside the turbo, the actuator would fail and stop communicating with the computer leading to excessive pressure between the engine and the turbo and potentially causing a blown head gasket.