What Causes Diesel Engine Generators to Overheat & How to Prevent it?

Diesel powered generators are known for their fuel efficiency, reliability and long life-span. However, that does not mean they do not experience problems starting and running. One problem is the potential for overheating. Overheating can be caused by a low level of coolant, improper use, or a problem with the generator.

Why is an overheating generator a bad thing?

If the generator starts overheating, the alternator will overheat, and it will burn out the windings affecting their insulating properties. The winding insulation will begin to soften, and then they can either melt or catch fire. When the slip rings and brushes are exposed to such a high temperature, they can unsolder themselves. Other problems you might encounter include:

• Warping of the rotor.

• Bearings start to melt.

• If the cylinder head overheats it could crush the head gasket resulting in restricted coolant flow to the cylinder.

• Overheating can cause damage to the radiator core.

• The exhaust valves will also expand damaging the valve guide.

Overheating of the generator can lead to damage to different parts of the generator which would need to be repaired or replaced. It is also worth noting that repair costs can sometimes exceed the cost of purchasing a new generator. If the generator shuts down, you will have to deal with the loss of power which could mean losses associated with downtime. Overheating can also shorten the lifespan of your generator significantly, meaning you have to replace it sooner than you had intended.

Common causes of overheating in diesel generators

Now that you know how much damage overheating can cause on a generator, you might want to know the causes of an overheating generator. They include;

1. Low coolant levels which could mean the coolant is leaking internally or externally. Leaking coolant could be a result of loose clamps or leaking gasket among other reasons.

2. Poor circulation of the coolant which could be caused by a collapsed soft hose leading to a restriction.

3. The diesel engine generator has accumulated dirt on its exterior. Heavy accumulation of grease and dirt on the surface of the generator hinders normal heat dissipation.

4. Over fueling the generator.

5. A broken cooling fan or improper fan belt tension.

6. Clogged diesel injectors. If the fuel injector is clogged, the system will have to overwork to compensate for the clogged injector which leads to overheating.

7. Clogged air filters can cause the generator to overheat and cut out.

8. Damaged exhaust that restricts exhausting.

9. Generator overload.

10. Low oil levels.

It is important to mention that a faulty gauge can lead to overheating because if the generator is overheating, but the gauge is faulty, it will not trigger the cooling system when the generator needs it. A faulty gauge could also indicate that the generator is overheating when it is actually within its normal operating temperature. When it is time to troubleshoot, ensure you double check the gauge.

The potential problem with the external environment

Environmental factors can also affect the functioning of a generator. In high altitude areas, air pressure drops hence reducing air density. With low air density, heat dissipation is not efficient. At a high altitude, heat dissipation happens at a much slower rate which results in the generator overheating.

In areas where there are high temperatures, there is lower air density. When there is inadequate air supply there will be less oxygen for combustion, the engine will push itself to deliver the same power, and it might end up overheating. High humidity also puts stress on the generator’s cooling system. When temperatures outside are hot, or there is high humidity, there is no significant difference between the coolant and the outside making it difficult to dissipate heat.

Read our genertaor maintenance tips for hot weather to keep your generator cool during hot summer months.

The potential problem with the inside environment

For a generator to cool off effectively, it requires air flow. Therefore, if the generator is in the basement, it is essential to ensure that the basement is well ventilated with proper air flow. If the air is flowing, the hot air around the generator will flow away being replaced by cooler air, enabling the generator to cool. It is also important to check if there are other equipment in the same room as the generator that could be emitting heat as well. If this is the case the temperature around the generator would be too high, potentially hindering its cooling system. The exhaust could also be blocked meaning that the generator is not able to effectively cool itself.

How to prevent a generator from overheating

Even though a generator is mechanical and is bound to fail every once in a while, there are some things you can do that prevent the diesel engine generator from overheating. The most important thing you can do to prevent your generator from overheating is having it serviced regularly by a professional and in accordance with the manufacturer’s instructions. Proper servicing not only keeps your generator running smoothly but it also extends its lifespan.

Other than regular servicing, here are other things you should do to prevent your generator from overheating.

• Keep both the coolant and oil levels at their correct levels.

• Monitor the exhauster to make sure that it is not blocked.

• Place the generator in a protected but well-ventilated area.

• Do not place the generator close to other equipment that emits heat.

• Run your generator regularly to make sure it is in good working condition.

• Do not overload the generator. If you need more power, replace your current generator with a more powerful one.

• Ensure you use quality fuel and coolant.

There are a number of things that can go wrong with a diesel-powered generator, but the most common one is overheating. It is essential that you implement the generator protection points listed above to give your generator a longer lifespan.

Having Problems with Your Diesel Generator?

Worldwide Power Products provides generator and engine service, maintenance, and repairs along the Texas Gulf Coast. Whether you need a one-off emergency repair in the middle of the night, a routine maintenance checkup, or a customized behind-the-meter power generation installation, we’re the folks for the job.

Learn more about WPP’s generator and engine service and repairs.