Emission Control Systems: Description and Operation

Engine Emission Control - 6.4L Diesel

The EGR system includes:

- EGR valve and EGR housing
- Horizontal EGR cooler assembly
- Vertical EGR cooler assembly
- EGR Oxidation Catalytic Converter (OC)

The EGR system reduces the peak combustion temperatures and Nitrogen Oxides (NOX). Due to emissions requirements, the EGR is used in over 80% of engine operation modes.

The exhaust gas is fed from the turbocharger up pipes through the EGR OC. This EGR OC helps to reduce the formation of lacquer in the EGR system by converting the heavy hydrocarbons into dry soot. This helps to improve the effectiveness of the EGR coolers. Refer to Exhaust System &/or Catalytic Converter.

The exhaust gas then enters the EGR coolers. The 6.4L has 2 coolers in series, in order to meet the exhaust gas cooling requirements. The EGR coolers are a shell- and tube-style heat exchanger.

The cooler EGR gas is then routed to the EGR valve that is mounted in the EGR housing. The EGR valve is used to control the amount of cooled exhaust gases that are introduced into the clean air stream.