The 6.7L Dodge Pickup is powered by a Cummins diesel engine that’s known for its performance and reliability. Even the best engines will succumb to wear and tear eventually, though, and pickup owners aren’t exactly known for going light on their trucks. If you regularly put this truck through its paces, you’ll eventually notice a repair or two that must be made. Here are some of the most common 6.7 Cummins problems that you’re likely to face.
Clogged Diesel Particulate Filter
Chrysler initially didn’t use diesel exhaust fluid (DEF) on 6.7L Dodge turbodiesel trucks, and the early versions of these trucks frequently get clogged diesel particulate filters (DPFs) as a result. DEF converts nitrous oxide, enabling diesel engines can use a wider air-to-fuel ratio yet remain within federal emissions standards. Not using DEF requires the early 6.7L Dodge trucks to operate within a more narrow ratio, which produces less nitrous oxide but more particulate matter. It’s the particulate matter that clogs the DPFs on these trucks.
Sticking Variable Geometry Turbocharger
The 2007 6.7L Dodge Ram was the first truck to sport Cummins’ variable geometry turbocharger (VGT), which was added to improve output while maintaining necessary airflow. VGTs are inherently more complex turbochargers that have multiple moving parts within them, and these parts eventually become covered with oil, soot and ash. Excessive buildup will make the parts stick, and performance will suffer and the engine will be more strained as a result. The VGT should be manually cleaned when it becomes sticky.
Both the VGTs and standard turbochargers on 6.7L Cummins engines are prone to break down, especially on earlier versions of the engine. Compromised oil seals, a damaged compressor wheel, a damaged turbine wheel, electronic problems and worn bearings can all cause turbo-related issues. When a turbocharger does break down, repair or replacement may be in order. A diesel service technician can advise you on which course of action is more appropriate.
Blown Head Gaskets
The higher cylinder pressures of the 6.7L Cummins engine make 6.7L Dodge trucks more prone to blow head gaskets than their smaller 5.9L siblings. Cummins included a larger bore and stroke to improve power output on the 6.7L engine, but more air and fuel are also needed to get the high torque that these Dodge trucks are known for. The increase of air and fuel raises pressures, and a few head gaskets will inevitably fail at times.