The 6.0L motor can be made right, however, it takes an owner with some determination to improve and understand their vehicle. Two of the most important systems to understand are the exhaust gas recirculation(EGR) and oil cooling systems. Both of these systems must dissipate heat from the motor in order to keep the horsepower harmony moving forward. In this article we will examine the EGR cooler.
The EGR cooler takes in hot exhaust gas and passes it through a heat exchanger. Engine coolant is used to extract heat from the hot mixture. The primary goal of the cooler is to prepare some of the exhaust gas mixture for reintroduction into the air intake. This system reduces the emissions at the tail pipe by diverting some unspent fuel back into the motor for combustion. The cooled exhaust gas is mixed with fresh air for the next cycle. Click here to see an animation of this process. The cooler is designed at the factory to withstand a certain number of heating and cooling cycles. As the parts fluctuate between hot and cold they also change dimensionally in size. This constant straining of the material as it changes size will eventually lead to failure over many cycles. The stock cooler shows a consistent pattern of failure at the seams of the internal cooling system. This problem is easily fixed with an aftermarket EGR cooler from Bullet Proof Diesel. They start with the body of a stock EGR cooler and remove the internals. From there the cooler design is greatly simplified. The factory unit is a complex radiator fin style system. Bullet Proof Diesel reworks the original cooler as a shell and tube style exchanger.
The stock cooler passes hot exhaust gas between the horizontal rows of fins. Engine coolant runs down the vertical columns between cooling fins. The point where the fin connects to the vertical column is also a thermal stress riser and a primary point for fatigue failure. When the cooler fails it opens a passageway between the intake of the motor and the engine coolant. Coolant inside of the cylinder can lead to blown head gaskets and white steamy smoke from the tail pipe. The shell and tube design is elegant and durable. Hot exhaust gas passes down the center of long tubes which run the length of the exchanger. Coolant runs around the outside of the tubes and cools the exhaust gas. It reduces the thermal stress risers and provides a radially uniform expansion. When the tube gets hot it expands equally about it’s cross section. This is the EGR cooler going on the resident test mule as a preventative maintenance measure. This will eliminate a point of failure and give the owner a boost of confidence when putting the truck to work.