TUBE AS 2W7964 - Caterpillar

1100 and 3100 Series Engines, 3208 Engines In All ApplicationsDuring cold starts, diesel engines will generally show some white exhaust smoke. Some white smoke is a normal condition and is not an indication of a mechanical failure. But, the amount of white exhaust smoke and its duration (time during which smoke is present) can some times cause complaints. The information that follows will permit you to determine (find) the causes for white exhaust smoke, and which of the maintenance aids is most acceptable to your needs.
Characteristics of White Exhaust Smoke
White exhaust smoke is made up of fuel vapors and aldehydes which are the result of fuel that is not completely burned during combustion. An ignition delay is often the cause for the incomplete (not complete) combustion. The ignition delay is the result of not enough heat within the engine to cause the fuel to burn at the correct time.
Abnormal and Normal White Exhaust Smoke
Ambient (outside) and engine temperatures are a major part of this condition. The temperatures given below are examples and some adjustments will have to be made in your analysis of your engine's condition.
At an ambient and engine temperature of 15°F (-9°C), white exhaust smoke can generally be seen for approximately 8 to 16 minutes with the engine at 1400 rpm idle speed. Lower ambient temperatures will increase the amount and duration of the white exhaust smoke. To decrease the duration, put a load on the engine. This increases the engine temperature more quickly for better combustion.
If the duration of white exhaust smoke is more than 20 minutes at 1400 rpm and the ambient and engine temperature is 15°F (-9°C), this is an abnormal condition. The engine must be checked for correct operation, and the fuel must be checked for low API gravity and/or cetane number.
If the duration of white exhaust smoke is 8 to 10 minutes at low idle and the ambient and engine temperature is 15°F (-9°C), you can either follow the same procedure for an abnormal condition or use one or more of the maintenance aids to improve the condition.
Troubleshooting the Abnormal Condition
If the white exhaust smoke is abnormal or not acceptable, work can be done to the basic engine or changes made to the fuel to decrease the amount and duration of white exhaust smoke.
1. Check the fuel quality, A.P.I. gravity and cetane number. See your fuel supplier to get the cetane number.Use a light diesel fuel or kerosene in the A.P.I. range of 41-44. The minimum cetane number for direct injection engines is 40. Fuels with these recommendations will cause less white exhaust smoke, improve the ability for the engine to start and to operate smoothly.
See Special Instruction Form No. SEHS7067, "Fuels for Caterpillar Diesel Engines" for a list of fuel recommendations.2. Check the fuel system timing. Make sure the timing is not retarded (slow). To get the best accuracy, use the fuel flow timing method. Put the setting at the high limit of 17°. The specification for 3208 Engines is