17.6 FAULTY EXHAUST SYSTEM 17.6 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, 127 - 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. Connect a manometer to the tapped hole. 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.
ENGINE EXHAUST To avoid injury from inhaling engine exhaust, always operate the engine in a well-ventilated area. Engine exhaust is toxic. 3. Start and run the engine at idle with a no-load for approximately 5 minutes, allowing the engine coolant to reach normal operating range. 4. Install the vehicle on a chassis dynamometer and run the engine speed to full load. [a] If the exhaust back pressure at full load is less than 10 kPa (4.0 in. H 2 O), check for high inlet air temperature; refer to section 17.7. [b] If the exhaust back pressure at full load is 10 kPa (4.0 in. H 2 O) or greater, refer to section 17.6.1.
17.6.1 Engine Exhaust System Resolution Perform the following steps to resolve the engine exhaust system: 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 section 17.6.1.1. (Rev. 2007) All information subject to change without notice. 17-18 From Bulletin 1–MBE 4000–07 6SE412 0702 Copyright © 2007 DETROIT DIESEL CORPORATION