EGR Valve: Testing and Inspection

Fig. 50 EGR Component Locations:

1. Connect a vacuum tester (pump and gauge) to the EGR valve and apply approximately 12 in. Hg. The EGR valve must be able to maintain the vacuum.
2. Disconnect the tester vacuum line.

^ The EGR valve should close (audible click). If not, replace the valve.

3. Start the engine and run at idle speed.
4. Apply approximately 12 in. Hg to the EGR valve.

^ The engine should run noticeably rough.

a. If the engine does not run rough check for plugged EGR recirculation lines.
b. If the lines are not plugged replace the EGR valve.

5. Connect a vacuum tester (gauge) with a "Y" fitting to the EGR valve.
6. Start the engine and slowly increase engine speed to approximately 4000 RPM.

^ Tester should indicate vacuum, if not continue with step 7.

7. Stop the engine and disconnect the vacuum line from the "Throttle Valve" which leads to the 50°C (122°F) thermovalve and apply approximately 12 in. Hg with a vacuum pump.

^ With the coolant temperature above 50°C (122°F) a vacuum of approximately 12 in. Hg should be indicated at the EGR valve. If not check the vacuum lines and the 50°C (122°F) leaks or restriction.