Diesel Engine Generator – What Bad Fuel Does To Your Generator

Owning a diesel engine generator is quite a capital intensive investment. Because it does not come as cheap like their other fuel-type counterpart e.g. petrol and gas engine generator, care must be taken to ensure they are always ready to serve their purpose.

As you likely know, all internal combustion engines get its power from series of complex combustion processes. When this process is disrupted, there will be no proper combustion, the ignition will be interrupted and lots more damages could ensue. All these can cause performance related problems in your generator and in extreme cases, it can damage the generator totally.

Since bad fuel does not properly combust, these are the effects of bad fuel on your generator:

  1. Reduced engine power:

Bad fuel will not burn completely and combust fully as high-quality fuel. As a result, there is bound to be reduction in the performance of the engine as well as power output. Thus, a good quality fuel is needed for the proper combustion. Anything short of quality fuel will mar standard engine performance and will reduce the engine power.

  1. Hard-starting:

Hard starting is another symptom of bad fuel in the engine fuel tank. Ignition depends on steady flow of clean, high-quality fuel in the cylinder. Bad fuel with low octane or high in water content can prevent a generator from starting properly.

  1. Engine hesitation:

The engine tends to hesitate and tend towards shutting down especially when you add more load to it. The generator will not respond because something is wrong somewhere. Fuel with insufficient octane will reduce combustibility and hence will cause the engine to hesitate.

  1. Engine pinging:

One of the major symptoms of bad fuel in a car is engine pinging, or producing a knocking sound. This occurs as a result of incomplete combustion. There is no sufficient burning of fuel and air mixture inside the engine cylinders. This will result to potential knocking of the engine, especially when the engine is loaded.

  1. Illumination of the check engine light:

Bad fuel in a generator set can be one of the numerous causes of check engine light on the key module/power wizard of your generator.


  1. Reduced fuel economy.

Bad fuel increases results in an increase in fuel consumption as controller tries to compensate for quality fuel at the injector.

  1. Higher emission

To forestall all these potential risks to your generator set, it is best to always use the correct octane-rating fuel for your generator set and you should always buy good quality fuel from a reputable filling station. Black market is known to be the deadliest fuel you can use for your generator.

Some filling stations too are full of scam. Their common scam is to fill their underground tank with premium fuel and then dilute it with lots of lower octane fuel. Don’t be a victim. It is best to ensure that your generator is reasonably protected by installing a fuel-water separator to curtail the likelihood of bad fuel entering your engine.