Maintenance Tips for Diesel Generators

Diesel generators are famous for their reliability and extended use. However, for these generators to last as advertised, they need to be well maintained.

This guide gives some insights into the essential upkeep practices to prolong a generator’s life by preventing problems before they arise through constant maintenance. 

Diesel Generators Maintenance: An overview

Before we get into the diesel generator maintenance checklist, it should be clear that maintenance aims to keep the generator in top shape instead of waiting for issues to occur before fixing them.

Unlike general house appliances, where you address an issue whenever it arises, diesel generators are complicated machinery that can sustain heavy damage if the (fix the issue only when it happens) approach is taken with them.

If you utilize that approach, many parts of the generator may already be damaged before you start noticing that something is off.

That being said, the diesel generator maintenance procedure involves two primary aspects: regular inspections and weekly/monthly/annual maintenance.

Regular Inspections of Diesel Generators

A good practice to ensure the operational longevity of diesel generators is to regularly inspect the generator even if nothing seems out of order.

These checks involve inspecting any corrosion, faulty connections, or signs of leaks. Exhaust systems, fuel lines, and filters are also among the parts that need regular inspection. 

Cleaning critical components like battery terminals, exhaust outlets, and air vents is a feasible practice during the inspection as well. 

The frequency of such checks depends on multiple factors that include, but aren’t limited to:

  • The manufacturer’s manual: The generator’s manual is the primary source of information. It will tell you what parts to check and how often.
  • The environmental conditions: Generators operating in the open are more subjected to dust and weather elements than ones in hangers and buildings. As such, more frequent inspection is required.
  • Containerized vs. regular: Containerized generators are specifically made to resist weather elements. As such, they may require less inspections. 
  • Portable vs. standby diesel generators: standby generators are often subjected to heavy loads compared to portable generators, requiring more frequent inspections. 

The Diesel Generator Maintenance Schedule

You should conduct the scheduled maintenance at specified intervals, either service hours e.g. (50,250,500,…) hrs, or service periods e.g. (weekly, Monthly,…), whichever comes first. 

Refer to the manufacturer’s operation and maintenance manual for more details. 

The Weekly Maintenance Checks

Weekly maintenance checks often don’t require any part replacements. They involve checking the overall appearance of the generator, looking for any signs of leaks, and ensuring that all fluid levels are appropriate. 

The Monthly Maintenance Checks

Some generators require replacing oil every month. This is especially common for standby generators that are constantly under heavy load.

You should also inspect the battery and coolant. Regarding the battery, ensure the wires are connected properly and that no fluid is leaking.

As for the coolant, you should check the antifreeze-to-water concentration ratio. The optimum ratio is decided by the generator type, model, and region.

If you’re not planning to use the generator for a while, you should run it under 50% load at least once per month. This maintenance run keeps the engine lubricated and prevents rust from accumulating on the components. 

The generator should remain under 50% load for at least 30 minutes during the maintenance load. Whenever applicable, you should also check the following parameters:

  • Starting ability: check if there are any errors during start-up.
  • Warning signs: check the display for any warning alarms that may denote a problem.
  • Electrical parameters: ensure that wiring and connections have no faults.
  • Indications: make sure that parameters like oil pressure, water temperature, oil temperature, and exhaust temperature gauges are within normal ranges throughout the 30 minutes of load. You should also check the tachometer and exhaust color.
  • Abnormal noise: Check for any abnormal noise or vibration during operation. 

The Annual Maintenance Checks

Annual maintenance is where most maintenance tasks are performed. Unlike visual inspection, deep inspection and potential part replacement are best left to a certified professional. That being said, here is the annual maintenance checklist:

  • Deep inspection of the wiring, air intake system, and the electrical system.
  • Deep and thorough cleaning of the generator.
  • Changing the oil filters and the oil itself.
  • Performing load bank and function testing. 
  • Deep inspection of fuel lines and hoses for any cracks or leaks, replacing any if damaged. 

Additional Maintenance Tips for Diesel Generators

Here are some additional maintenance tips for diesel generators beyond the basics of oil changes, filter replacements, and regular inspections:

Fuel System 

Whenever you refuel your electric diesel generator, ensure that the fuel you have is of good quality.

If you doubt that your fuel has impurities or water contamination, pour some of it into a transparent cup and wait a few minutes. Water and impurities will deposit near the bottom of the cup. 

Moreover, if you’re not planning to use your diesel generator for a while, consider emptying and storing its fuel to prevent it from precipitating in your fuel system. You should also drain and clean the fuel tank every few months to eliminate the possibility of blockages. 

Cooling System

Much like the fuel system, you should flush the cooling system regularly to remove rust, scales, and various other contaminants that can render your generator less efficient.

You should also inspect the radiator fins for blockages and regularly clean any dirt or debris to prevent airflow obstructions.

Electrical System

Since corrosion can build up on battery terminals, you should inspect and clean them often. While the generator is off, use a baking soda solution and a wire brush to clean the battery terminals. 

Checking the voltage is also a good idea, especially if your generator is struggling to fire up. 

Overall General Maintenance 

If you’re diesel generator is portable, you should store it in a cool, dry place if you’re not using it. This reduces the risk of rust and moisture damage. 

For standby generators, the user shall refer to the preservation and storage instructions found in the user’s manual. 


What Maintenance Is Required For a Diesel Generator?

The maintenance required for a diesel generator involves checking the fuel, cooling, and electrical systems for faulty or leaking components. You should perform these Inspections on a weekly and monthly basis, and daily for generators under constant load. 

There’s also the annual maintenance, which involves an oil change, deep cleaning, thorough inspection, and load bank and function testing. 

How Do You Take Care Of a Diesel Generator?

You take care of a diesel generator by following the guidelines in the manufacturer’s manual, using high-quality fuel, performing regular inspections, and replacing necessary parts when damaged or during annual inspections. 

Final Words

Regular maintenance is crucial for prolonging the life of diesel generators. Following the manufacturer’s guidelines for inspection frequency allows you to catch issues before major damage occurs.

Weekly and monthly checks involve inspecting for leaks, corrosion, and fluid levels, and replacing oil, filters, and spark plugs. Annual deep cleaning and part replacement by professionals are recommended. For more information about diesel generators, visit Precision Industries’ official website. You can also browse our storefront to check our premium range of highly versatile diesel generators.