Usage:
White Smoke
Too Much White Or Blue Exhaust Smoke
1. Cold Outside Temperature
White smoke is normal in cold temperatures until the engine warms up. There will be less white smoke if No. 1 diesel or blended fuel is used.
2. Engine Running Too Cold
Check the water temperature gauge in the cab. If the temperature remains below the minimum value of the gauge after a reasonable warm up time, this could indicate an open thermostat. Remove and test the thermostat. See the topic, Testing The Cooling System, in 3176 Diesel Truck Engine Systems Operation And Testing and Adjusting, Form No. SENR3909.
3. Air In Fuel System
Disconnect the fuel return line at the tank. Place this end of the line in a container of fuel to see if air bubbles are present when the engine is running. If air bubbles are observed, check for loose fittings or line leaks between the fuel tank and fuel transfer pump. If leaks are found, tighten the connections or replace the lines.
To remove air from the engine fuel system: With the engine off, loosen the fuel return line fitting at the fuel manifold. Operate the fuel priming pump until the flow of fuel is free of air. Tighten the return line fitting, fasten the priming pump, and start the engine. If the engine still does not run smooth or produces a lot of white smoke, apply 35 kPa (5 psi) of air pressure to the fuel tank to force fuel through the system.
| NOTICE |
|---|
Do not use more than 55 kPa (8 psi) of air pressure in the fuel tank or damage to the tank may result. |
Check the fuel return line for restriction. Replace if plugged.
5. Fuel Injection Timing Out Of Calibration
Check the fuel injection timing calibration and make necessary adjustments. See the topics, Engine Test Procedure Number P-402, [Checking Electronic Injection Timing With The Timing Adapter Tool Group And The ECAP (Electronic Control Analyzer and Programmer)], and Engine Test Procedure Number P-403, [Calibrating Electronic Injection Timing With The Timing Adapter Tool Group And The ECAP (Electronic Control Analyzer and Programmer)], in Electronic Troubleshooting, 3176 Diesel Truck Engine, Form No. SENR3913.
6. Valve Adjustment Not Correct
Check and make any necessary adjustments. See the topic, Valve Clearance Setting, in 3176 Diesel Truck Engine Systems Operation And Testing and Adjusting, Form No. SENR3909. Intake valve clearance is 0.38 mm (.015 in), and exhaust valve clearance is 0.64 mm (.025 in).
7. Defective Unit Injectors
A defective unit injector can be found, by running the engine at the rpm where the problem exists, with the use of the Electronic Control Analyzer and Programmer (ECAP) service tool Interactive Diagnostics feature (single cylinder cutout, see Electronic Troubleshooting, 3176 Diesel Truck Engine, Form No. SENR3913) to stop the fuel supply to each cylinder in turn. If a cylinder is found where the cutout makes no difference on the engine performance, that injector should be removed and tested. Drain the fuel supply manifold and remove the injector(s) (see 3176 Diesel Truck Engine Disassembly and Assembly, Form No. SENR3914).
Testing of the injectors must be done off of the engine. Use the 1U6661 Pop (Injector) Tester Group with a 1U6663 Injector Holding Block, and a 1U6665 Power Supply, to test the injectors. For the test procedure refer to Special Instruction, Form No. SEHS8867, Using The 1U6661 Pop (Injector) Tester. For test specifications refer to Special Instruction, Form No. SEHS8804, Unit Injector Test Specifications for 1.7 Liter Engines.
NOTE: Inspect and repair as necessary the sealing surface (seat) of the injector sleeve in the cylinder head when removing and installing an injector. The injector sealing surface (seat) must be free of scratches or evidence of combustion products. If it is necessary to rework (ream) or replace the sleeve use 4C4054 Tool Group and refer to Special Instruction, Form No. SEHS9120, Removal And Installation Of Unit Injector Sleeve.
The "check engine" light on the dash can be used to determine if there are any electronic system faults relating to the injectors. Fault codes 72, 73, 74, and 75 relate to the injector operation and wiring. See Electronic Troubleshooting, 3176 Diesel Truck Engine, Form No. SENR3913.
8. Misfiring Cylinder(s)
See the topic, Misfiring and Rough Running.
Blue Smoke
9. Engine Oil Level Too High
Check the crankcase oil level. Maintain the level between the FULL and ADD marks on the dipstick. If the oil level increases as the engine is used, check for fuel in the crankcase. See the topic, Fuel in Crankcase Oil.
10. Worn Valve Guides; Worn Or Damaged Pistons, Rings And/Or Liners, Turbo Shaft Seal Leakage
Oil leakage into the combustion area of the cylinder(s) can be the cause of blue smoke. Inspection of these components will require engine disassembly. Refer to 3176 Diesel Truck Engine Disassembly and Assembly, Form. No. SENR3914. See 3176 Diesel Truck Engine Specifications, Form No. SENR3908 for the maximum permissible wear of the valve guides.