ENGINE COMPONENT AND LOCATION 107 EGR Cooler The EGR valve is connected to the EGR cooler by the cooler inlet pipe. Using engine coolant, the EGR cooler lowers the temperature of the gas coming from the EGR valve. The cooler contains a series of vanes that increase cooling efficiency by swirling the hot gas before it enters the mixer. EGR Venturi System On leaving the EGR cooler, the gas flows through a venturi equipped with two pressure sensors. The venturi changes the speed and density of the flow. The sensors report the pressure difference to the EECU. EGR Cooler Outlet Pipe The EGR cooler outlet pipe carries the exhaust gas from the venturi to the mixer.
Relatively short, the tube passes over the valve cover, behind and into the mixer at the front end of the inlet manifold on the conventional chassis engine. Relatively much longer on the LCF, the tube passes from the venturi around the front of the valve cover and reaches back to the mixer at the rear end of the inlet manifold. A temperature sensor monitors exhaust temperature sending the data to the EECU. Excessively high temperature, or abnormally high temperature for more than 30 minutes during an hour, causes the EECU to limit engine power to prevent engine damage. EGR Mixer The EGR mixer is the meeting point for cooled, recirculating exhaust gas and outside air from the CAC.
From here, the combined gases pass into the inlet manifold and on to the combustion chamber.