Troubleshooting Common Issues with Diesel Generator Parts

Troubleshooting Common Issues with Diesel Generator Parts

What do you do when your diesel generator shows signs of a problem or simply won’t work? For you not to be caught off guard, you need to know the causes and their respective solutions. 

Common issues with diesel generator parts could stem from various areas or reasons. Therefore, a systematic troubleshooting and remedying process is necessary.  

Common Diesel Generator Problems

Engine Won’t Start 

Whether you have used the diesel generator for a long time or not, you could wake up one day and find it not working. Probable root causes are lower oil level, battery failure, depleted fuel, and issues with the fuel injection system. Others are a clogged air intake, circuit breaker issues, and a false alarm. 

Overheating Issues 

Overheating is a serious concern for diesel generator designers and users. Different parts of the unit can overheat and cause problems. For instance, the alternator can overheat and cause melted bearings, crushed head gasket, and warped rotor. Checking the thermostat and radiator regularly can help prevent this problem. 

Fuel System Problems 

Fuel system issues are also common in diesel generators, whereby there could be clogging in the fuel filter, air in the system, or obstruction in the fuel line. That’s why we always insist on regular filter changes and use of high-quality fuel. 

Electrical Failures 

When the electrical system of the diesel generator fails, there could be an issue with the circuit breaker/wiring or the battery. 

Diagnostic Steps for Diesel Generators 

Visual Inspection 

Here are some of the things to do during a visual inspection exercise:

  • Check for cracks, corrosion, and other forms of physical damage
  • Check for any leaks Oil/Coolant/Fuel
  • Check if there is any Loose electrical connections
  • Check for any obstructions that might impede air flow
  • Check for the presence of dirt and debris

Checking Fuel Levels 

For a diesel generator that won’t start, check also if the respective sensors are operating correctly. Sometimes, the fuel will have been consumed already but the sensor is not relaying this information. There could also be fuel leaks in the system. 

Examining Electrical Connections 

The electrical system is a core part of the diesel generator. A loose connection somewhere or a component that has malfunctioned can make the unit fail to start. Even more serious, an electrical connection issue can be hazardous. 

Using Diagnostic Tools 

Load bank testers, clamp-on ammeters, and multimeters are some of the must-have diagnostic tools. They come in handy for testing and troubleshooting for diesel generator part issues. For instance, you can use the multimeter to measure voltage at the battery terminals and alternator. 

Solutions and Fixes

Engine Troubleshooting Tips 

Remember also that there could be diesel engine-related issues such as a clogged air filter. Clogging limits air flow, consequently slowing down the combustion rate. Resolve or prevent this issue by regularly inspecting, cleaning, and replacing the air filter as needed.

Check the condition of the glow plugs too. These diesel generator parts are prone to wearing out. If you determine that they are in bad condition, go ahead and replace them. 

Resolving Overheating Issues 

Move any item placed close (about 2 meters) to the air inlet and exhaust. The other sides of the diesel generator should have a clearance of at least 1.5 meters from objects. Clear any debris close to the equipment. You also need to ensure the correct levels for water coolant and oil. As you also replace the old filter, consider if you have been overloading the diesel generator, and adjust accordingly. 

Fixing Fuel System Problems 

Ensure sufficient supply of fuel by refilling the tank regularly. Check the fuel gauge frequently to ensure it is running normally. It is paramount to only use high-quality fuel to prevent injector and filter blockages. Use the manufacturer’s recommended methods to remove air pockets in the fuel system. 

Repairing Electrical Components 

Repair the most commonly faulty electrical components. These diesel generator parts include the starting motor, alternator, voltage regulator, and drive belt. Based on the results of the diagnosis, you may need to repair some of these parts. 

Preventive Maintenance Tips

Regular Inspections (Daily, weekly, monthly, quarterly, or Annually) 

The frequency of these inspections depend on the operational conditions and the manufacturer’s recommendations. These help discover potential problems with diesel generator parts before they escalate. Corrosion, leaks, and loose connections are some of the tell-tale signs from regular inspections. 

Load testing should be performed at least annually on the larger generators, the goal being to ensure the generator performs under expected operating conditions. 

Fuel System Maintenance 

The condition of the fuel system largely affects the running and longevity of the unit. Keep it in good shape through the use of quality fuel and fuel stabilizers, among other measures. 

Electrical System Upkeep 

It is equally important to maintain the battery and other electrical components of the diesel generator. These are the voltage regulator, wiring, and battery charger among others. 


There is a sense of happiness for a diesel generator owner in knowing that the device will run as expected any time. The secret is in recognizing the possible issues and how to tackle them. Remember to always use OEM (Original Equipment Manufacturer) parts or approved replacements for optimum reliability and longevity of the diesel generator.

Related FAQs

  1. What are common diesel generator problems? 

Common diesel generator problems include electrical failures, fuel system issues, the engine failing to start, and overheating issues. 

  1. How can I troubleshoot a diesel generator that won’t start? 

For a diesel generator that won’t start, check the battery, fuel level, and engine overheating. 

  1. What should I do if my diesel generator is overheating? 

To counter unit overheating, clear blockages in the vicinity, maintain correct levels of water coolant and oil, change the air filter, and avoid overloading the diesel generator. 

  1. How often should I perform maintenance on my diesel generator? 

There are daily pre–start checks such as walking around. For a standby generator, these checks can be done weekly. A standby generator that has not been running needs an operational check bi-weekly. If a unit has not been on load, an operational and load check is required monthly. 

  1. What tools are needed for diesel generator diagnostics? 

Common tools for diesel generator diagnostics are load bank testers, clamp-on ammeters, and multimeters.