EGR Valve: Testing and Inspection

TEST PROCEDURE
- Disconnect vacuum hose from EGR valve.
- Connect a hand vacuum pump to EGR valve.

NOTE:
DO NOT run engine during this part of test.

- Using hand vacuum pump, apply vacuum to EGR valve.
^ Vacuum should hold without dropping.

If vacuum drops, or will not build up:
- Check hose connections for leaks
- Check vacuum pump operation

If pump and lines are OK:
- Replace EGR valve

If vacuum holds:
- Release vacuum.
- Start engine and let Idle.
- Using hand vacuum pump, briefly apply vacuum to EGR valve.
^ Idle must become rough and/or engine dies.

If Not:
- Check EGR valve for blockage.
- Check tube from exhaust manifold to EGR valve for blockage.
- Check passage in the intake manifold for blockage.