Exhaust Gas Recirculation: Service and Repair

Fig. 24 EGR control valve:

EGR CONTROL VALVE
The EGR control valve should be checked for deposits with particular attention to the poppet and seat area, Fig. 24. If deposits exceed a thin film condition, the EGR valve should be cleaned. If wear of the stem or other moving components is noted, the EGR valve should be replaced. Extreme care should be exercised during the cleaning operation to prevent spilling of solvent on the valve diaphragm, as this will cause diaphragm failure. Do not push on diaphragm to operate valve, use the vacuum source only.