EGR Valve: Testing and Inspection

WARNING: It the EGR valve is hot, wear gloves to avoid burning fingers.


PROCEDURE
1. Start the engine.
2. Run the engine until normal operating temperature is attained.
3. Place a finger on the Exhaust Gas Recirculation (EGR) valve diaphragm and accelerate the engine. The diaphragm should move.
4. Disconnect the vacuum hose from the EGR valve.
5. Using a hand vacuum pump, apply 27 kPa (8 in. Hg.) of vacuum to EGR valve with finger on diaphragm. The diaphragm should move and engine should run rough and may stall.

INSPECT
^ Check for carbon deposits in the valve which may cause a restriction in flow. The restriction may be small enough so that the engine may not stall during Step 5, yet large enough to cause a DTC to set. If the valve passes the above test, check the Exhaust Gas Recirculation (EGR) pressure transducer. Replace the valve if it fails the above test.