What Causes Generators To White Smoke? – Emergency Diesel Generators
Smoke from a diesel generator indicates engine health; clear exhaust means efficient fuel burning. Initial start-up may produce temporary smoke, but continuous visible smoke indicates issues. Black, blue, and white smoke points to specific problems: black signifies poor combustion, blue indicates oil intrusion, and white signifies incorrect fuel burning. Solutions involve adjusting fuel lines, replacing gaskets, and checking fuel quality. Common causes of smoke include incomplete combustion, low fuel quality, overloading, cold starts, injector issues, air intake restrictions, and engine wear. Regular maintenance helps prevent smoking.
Even when it is not visible, smoke of your diesel generator is present. When you cannot see that smoke, it is a good sign that everything is working as it should in the engine as this is health. It means that the engine is burning the fuel properly and the engine is blowing away the different fuel particles that corrode the engine.
In a modern diesel engine, with the emissions regulations so tight and strict, the exhaust gas will come out clear which shows that the exhaust gas is free from any contamination such as an un-burned fuel.
It is perfectly normal for smoke to be produced during the first few seconds following start-up as diesel fuel in the cylinders is burned off. But this should clear very quickly into a translucent emission (see second video below), but what about if it does not clear off? What about if your diesel generator is smoking (White, Black or Blue) whilst running? Then there are issues that you need to address.
You may also see some additional smoke when a heavy load is dropped onto the generator. This is because the generator has to adjust its fuel consumption to provide the additional power required to support the new load. Then after a few seconds, the exhaust smoke again becomes translucent, virtually invisible. In normal use a generator should not produce continuous visible smoke from the exhaust silencer.
The colour of the generator smoke will usually help you to identify the cause of the problem. For example:
BLACK SMOKE– poor diesel combustion caused by an air/fuel ratio imbalance.
BLUE SMOKE– oil entering the combustion chamber and burning.
WHITE SMOKE – fuel isn’t burning correctly and is passing through the diesel engine and exhaust unburnt.
How to fix generator smoking issues:
BLACK SMOKE– Adjust the fuel lines and fuel input. Replace the fuel filters AND air filters. Check the quality of the fuel, because dirty and contaminated fuel is often the main thing to fix before following our other suggestions. Next, check the injectors and replace if necessary. Look for signs of ageing and contamination.
BLUE SMOKE – Replace the head gasket and any gasket/seal around the fuel filters and oil filters as soon as possible. Failure to replace will cause major generator failure and result in the costly replacement of parts.
WHITE SMOKE – Check the fuel supply and adjust to allow less fuel into the diesel engine. Also, check for water leaks that may have found their way into the fuel tank or engine block. Tighten jubilee clips around hoses. Check hoses.
Click the video below to see a generator WHITE smoking:
Generator White Smoke from Power Continuity Ltd on Vimeo
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Click the video below to see what NORMAL generator smoke should look like on start up:
110kVA Start-Up black smoke to clear from Power Continuity Ltd on Vimeo
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This are some reasons why a diesel generator could be smoking:
Incomplete combustion- Insufficient air or improper fuel air mixture can result in incomplete combustion, leading to smoke emissions. This can happen when the generator is not properly maintained.
Low quality fuel- The quality of diesel fuel can be a huge cause of smoking and combustion efficiency. Poor quality fuel or contaminated fuel with impurities can generate smoke when burned.
Overloading- If a diesel generator is operating beyond its capacity or handling a sudden surge in power demand, it can lead to incomplete combustion and smoke generation.
Cold Starting- During cold starts, diesel engines may produce smoke until they reach their optimal operating temperature. This is because the fuel combustion process is less efficient at lower temperatures.
Fuel injector issues- Problems with fuel injectors, such as a clogging or improper spray patterns, can cause inefficient combustion and result in smoke emissions.
Air intake issues- Insufficient or restricted airflow to the engine can disrupt the combustion process and lead to smoke production.
Engine Wear and Tear-As diesel engines age or undergo inadequate maintenance, components such as piston rings, valves, or turbochargers may deteriorate. This can affect combustion efficiency and contribute to smoke production.
All of these reasons will cause the generator to smoke on a different way and in a different colour. So, what do the different colours mean?
Regularly serviced & maintained generators by PowerContinuity never smoke!