MBE 4000 DDEC VI Troubleshooting – Section 13.8 Faulty Exhaust System

Section 13.8
Faulty Exhaust System

To determine if a faulty exhaust system is causing lack of power, perform the following steps:‪

1. Drill an 11/32 in. hole in the exhaust pipe, 125-305 mm (5-12 in.) from the turbocharger exhaust outlet.

   Note: The tapped hole must be in a comparatively straight area of the turbocharger exhaust outlet.

2. Tap the hole to accommodate a 1/8 in. pipe plug.
3. Connect a manometer calibrated to read pressure in kPa or inches of Hg.

   PERSONAL INJURY ‪
   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.‪

4. Start and run the engine.
5. Run the engine at idle with a no-load condition for approximately five minutes, allowing the engine coolant to reach normal operating range, approximately 88-96°C (190-205°F).
6. Run the engine speed to full load.
   1. If the exhaust back pressure at full load is less than 12 kPa (3.5 in. Hg), check for high inlet air temperature; refer to "13.9 High Inlet Air Temperature" .
   2. If the exhaust back pressure at full load is 12 kPa (3.5 in. Hg) or greater, refer to "13.8.1 Engine Exhaust System Resolution" .

Section 13.8.1
Engine Exhaust System Resolution

Perform the following steps to resolve the engine exhaust system concern:‪

1. Visually inspect the engine exhaust system; refer to OEM guidelines.
2. Repair or replace defective exhaust system components; refer to OEM guidelines.
3. Verify exhaust system resolution; refer to "13.8.1.1 Test the Engine with Replaced Exhaust System" .

Section 13.8.1.1
Test the Engine with Replaced Exhaust System

Perform the following steps to determine if replaced engine exhaust system components have resolved the lack of power condition:‪

PERSONAL INJURY ‪
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.‪

1. Start and run the engine.
2. Test drive the vehicle to ensure lack of power has been resolved.
   1. If no lack of power occurred during the test drive, no further troubleshooting is required. Shut down the engine.
   2. If lack of power occurred during the test drive, shut down the engine. Check for high inlet air temperature; refer to "13.9 High Inlet Air Temperature" .