EGR Valve: Description and Operation

EGR Valve Flow:

EGR Valve Assembly Sectional View:

DESCRIPTION
The EGR Valve regulates the amount of exhaust gas fed to the engine. This mixture is dependent upon the height of the pintle above the orifice in the base of the valve.

OPERATION
Engine vacuum draws exhaust gases through the EGR feed pipe into the throttle body spacer where they mix with the incoming air charge and are distributed equally to each cylinder.

The bobbin and coil (solenoid) assembly is encapsulated to maximize reliability, to seal the coil from the environment, and to prevent movement of the coil and terminals. Inside the solenoid (bobbin and coil) assembly is an armature assembly, consisting of a pintle and valve assembly, two seals, retaining washers, a seal spring, an armature spring, and a bearing. The valve pintle shaft is sealed from the exhaust chamber by a bearing. In addition, an armature shield, held in place by a compression spring, deflects exhaust gas from the shaft and the armature. The base adapter and base plate make up the base assembly.

The PCM controlled EGR Valve offers more precise EGR flow metering than a back pressure or digital type valve and superior emission control and driveability.