EGR Valve: Testing and Inspection

Note: A split or porous diaphragm is the usual cause of EGR valve failure.

1. Remove the vacuum pipe from the EGR valve.
2. From underneath the valve, push up and hold the diaphragm in position.
3. Block off the vacuum pipe outlet.
4. Release the diaphragm; it should remain where it is. If it does not, air is escaping through the diaphragm. Renew the EGR valve.