Faulty EGR Valve
To determine if a faulty EGR valve is causing excessive black or gray smoke, perform the following:
- Remove the EGR valve; refer to MBE 900 Service Manual (6SE9007), exhaust gas recirculation (EGR) components chapter.
- Inspect the EGR valve flap for freedom of movement.
- If freedom of movement is restricted remove soot and clean deposits as required.
- If movement of valve is still not free, replace the EGR valve, refer to MBE 900 Service Manual (6SE9007), exhaust gas recirculation (EGR) components chapter. Verify the replacement of the EGR valve corrected the excessive exhaust smoke concern; refer to "9.9.1 Test the Engine with Replaced EGR Valve"
Test the Engine with Replaced EGR Valve
Perform the following steps to determine if the replaced EGR valve resolved the excessive exhaust smoke condition:
To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.
- Start and run the engine.
- Run the engine at idle under no-load conditions for approximately five minutes, allowing the engine coolant to reach normal operating range, approximately 70-95°C (158-203°F).
- Visually inspect exhaust for excessive smoke.
- If the engine smoke emission appears normal, no further troubleshooting is required. Shut down the engine.
- If the engine exhaust smoke is excessively black or gray, shut down the engine. Check the exhaust brake valve; refer to "9.11 Faulty Exhaust Brake Valve" .
|EPA07 MBE 900 DDEC VI Troubleshooting Guide - 6SE580|
|Generated on 10-13-2008|