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.