Exhaust Gas Recirculation: Testing and Inspection

Fig. 32 Testing The EGR Valve:

EGR VALVE INSPECTION

1. Remove the EGR valve from the vehicle and check for sticking, carbon deposits, or obvious damage. If necessary clean the valve with a suitable solvent.
2. Connect a hand vacuum pump to the EGR valve. Apply 67 kPa or 19.4 in. Hg of vacuum and verify that the diaphragm chamber is leak tight.
3. Apply 8 kPa or 2.4 in. Hg of vacuum and verify that air will not pass through the valve.
4. Increase vacuum to 23 kPa or 6.8 in. Hg and verify that air will pass through the valve.
5. Re-install the EGR valve and torque to 7 - 11 Nm or 5 - 8 ft. lbs.

Fig. 30 Testing The Thermo Valve:

THERMO VALVE INSPECTION

1. Disconnect all vacuum hoses from the thermo valve.
2. Connect a hand vacuum pump to nipple 'B'.
3. While the engine is cold (coolant temperature less than 63 degrees C or 145 degrees F) apply vacuum and verify that vacuum leaks.
4. Warm the engine up (coolant temperature greater than 65 degrees C or 149 degrees F) and verify that vacuum holds.

Fig. 56 Testing The Vacuum Regulator Valve:

VACUUM REGULATOR VALVE INSPECTION

1. Disconnect the white striped vacuum hose from the VRV and connect a hand vacuum pump to the nipple the vacuum hose was removed from.
2. Apply 53 kPa or 7.7 in. Hg of vacuum and verify that while the engine is stopped vacuum leaks and when the engine is running at 3,500 rpm that vacuum holds.