What May Cause Unusual Diesel Generator Smoke?

Normally, you won’t see any smoke emitted by modern diesel generators which are equipped with exhaust after-treatment systems during operation. The exhaust gas of a well-maintained diesel generator using good quality fuel should be almost colorless and transparent under normal operating conditions. When unusual smoke, such as white smoke, black smoke and blue smoke, occurs, it indicates some problems in your engine. Read on and learn more about the causes of unusual diesel generator smoke and how to fix the issues.

Why does a diesel generator blow white smoke?

Typically, the reasons for the white smoke from the generator include diesel not being burnt correctly in the cylinders or water in the fuel. Many factors could contribute to the white smoke. For example, if the compression ratio or injection timing isn’t correct, or there is something wrong with the fuel pump or injector, it could result in un-burnt fuel in the exhaust gas, causing the white smoke. Additionally, if there is some water within your fuel system, the exhaust gas also appears white. 

To fix the problem, you need to find out what is the cause of this and take corresponding measures. If the fuel injector is not working properly, adjust or replace it. If air filter is clogged or dirty, replace it to ensure proper airflow. If there is water in the fuel tank or engine block, check for leaks and blockages. Tighten jubilee clips around hoses. Also consider fitting a racor fuel filter to remove water.

What would cause a diesel generator to emit black smoke?

Black smoke from a diesel generator generally indicates that the fuel is not properly atomized or not completely burnt. It’s also indicative of engine overload or an imbalance in the air / fuel ratio. The diesel engine could be delivering too much fuel, not enough fuel, too much air or simply not enough air. The common causes of black smoke include poor quality fuel, clogged air filter, incorrect injection timing, defective injector or injection pump, inadequate air circulation, over-fueling the engine, damaged intercooler, low compression in the cylinder, cracked or clogged valves in cylinder head, excessive engine sludge build up, etc.

To solve the problem, you need to check for the relevant worn or damaged components and replace them immediately if any is found. Keep in mind that service air, fuel and oil filters regularly and adjust valve clearance according to regulations. Adjust the fuel lines and fuel input if necessary. Check and calibrate the injector if the diesel engine is overloaded. Adjust the fuel supply advance angle if the fuel supply time is too late.

How do you stop blue smoke from your diesel generator?

If blue smoke from diesel generator occurs, it indicates that oil gets into the combustion chamber and is burnt in the cylinders. The oil can enter the combustion chamber due to a number of reasons, such as worn cylinders, worn piston rings, incorrect grade of oil, fuel dilution in the oil, bad valve stem seals, too high oil level, defective supply pump, operation under 30% of the load, glazed cylinder, glued segment and so on.

Blue smoke is common when you start the diesel engine in a cold weather. A diesel generator that runs without load or with low power for a long time is also more prone to blue smoke problem, as it does not reach normal operating temperature and will not have sufficient expansion in the pistons and segments.

Since there are many possible causes for blue smoke from your diesel generator, you may fail to fix the issue by yourself. It’s suggested that you consult an experienced technician to diagnose and solve the problem. Generally, the blue smoke can be fixed by replacing engine oil seals, replacing piston rings, replacing valve stem seals, replacing glow plugs, replacing blown head gasket, repairing turbocharger, discharging the excess oil, using inlet manifold sealant or replacing the part, etc.

Abnormal diesel generator smoke should not be ignored. When white smoke, black smoke or blue smoke occurs during generator operation, it means that there may be a problem that could damage the equipment or increase the operating costs. You need to address yourself to the problem of unusual smoke, ensuring the proper running of your generator and extending its lifespan. Don’t hesitate to reach out for any further information or assistance regarding to diesel generators. Contact us at dingbo@dieselgeneratortech.com, and we will gladly help you.