S 500 Coupe (140.070) V8-5.0L (119.970) (1995)
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EGR Valve: Testing and Inspection
EGR Valve (89)
EGR VALVE TEST
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.
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.
Engine should run noticeably rough
If the engine does not run rough replace the EGR valve.
ELECTRICAL COMPONENTS
See COMPUTERS AND CONTROL SYSTEMS.
