Before running
- Visible fuel, oil or coolant leaks
- Fuel level
- Oil level
- Coolant level
- Alarms already on the controller
Updated
Diesel maintenance
Diesel Generator Maintenance Checklist
Typical diesel generator maintenance runs on three rhythms: daily checks of oil, coolant, the air cleaner indicator, belts and the water separator; draining water and sediment from the fuel tank every 50 hours or weekly; and a minor service every 500 hours, as Perkins publishes. The manual for your engine gives its exact list and intervals.
Callout fee waived when you accept our written quote. 1-year workmanship guarantee. See prices
- Daily, weekly and 500-hour work
- Water in diesel caught early
- Standby sets kept ready
- Onsite across Gauteng
Readiness, not only an oil change
What belongs on a diesel maintenance list?
Before each run, look for leaks, check the fuel, oil and coolant levels with the engine cool, and read any alarm already on the controller. These are visual checks. Leave the radiator cap closed on a warm engine, and never bridge a shutdown.
Diesel fuel needs more attention than petrol because it holds water, and water feeds diesel bug. Draining the water separator and the tank on schedule removes the layer that blocks filters and damages injectors. Perkins lists the fuel-tank drain every 50 service hours or weekly.
At the service we change the oil and filters that are due, inspect belts, hoses, coolant, the battery and charger, and check voltage and frequency on a run. When you need proof that the set can carry your building, we book a load bank test.
Diesel-specific attention
Fuel, control and output
Diesel condition
Water, dirt and microbial growth show up as blocked filters, hard starting and smoke. We check the tank and the separator as well as the spin-on filter.
Lift pump and injector symptoms
A set that cranks and starves, or smokes and runs rough, needs a diagnosis. We record the symptom, find the cause and quote injector or pump work separately.
Controller and ATS
We read the alarms and service hours and confirm the set is left in automatic. On a standby set with an ATS, we test the changeover as a controlled check.
Load and output
We record voltage and frequency on a run, and load behaviour where the site can apply load safely. A loaded run proves a diesel that must carry a building; an idle start does not.
Typical published diesel maintenance intervals
These are published schedules for particular engines and standards. They show the typical rhythm of diesel maintenance. Your own engine’s manual gives the exact items and figures for your set.
| Interval | What it includes | Who does it | Source |
|---|---|---|---|
| Daily | Coolant level, engine oil level, air cleaner service indicator, V-belts, primary fuel filter or water separator, driven equipment, walk-around inspection | You or a site operator, with the engine stopped and cool | Perkins: How do you maintain a Perkins engine? |
| Every 50 service hours or weekly | Drain water and sediment from the fuel tank | Site operator or technician | Perkins: How do you maintain a Perkins engine? |
| Monthly | Exercise run loaded to at least 30% of the standby nameplate rating (US NFPA 110) | Site operator or technician | EC&M: Testing generators with a portable load bank (quoting NFPA 110, 2013 edition) |
| 240 operating hours | Oil and filter change in continuous emergency use | Technician | FEMA IS-815: generator servicing requirements |
| 500 hours | Perkins minor service | Technician | Perkins: How do you maintain a Perkins engine? |
| 1,000, 2,000, 3,000 and 4,000 hours | Perkins major services | Technician | Perkins: How do you maintain a Perkins engine? |
A set in near-constant use reaches these hour points far sooner than a standby set, so standby diesels usually come due on the calendar first.
Diesel maintenance checks
Operator checks are visual and level checks with the engine stopped and cool. Filter changes, electrical tests and anything under the cooling cap are for the service visit.
Periodic engine checks
- Engine oil
- Oil filters
- Fuel filters
- Water separator, where fitted
- Air filter
- Belts and hoses
- Coolant and radiator
- Battery, charger and terminals
Fuel system
- Diesel condition
- Water or contamination
- Tank condition
- Fuel lines
- Lift-pump symptoms if it starves
- Injector symptoms if it smokes or runs rough
Control and output
- Controller alarms
- Hour reading
- Automatic mode on a standby set
- ATS operation, where fitted
- Voltage and frequency
- Load performance, or a load bank test when capacity is the question
Related Pages
Diesel repairs, servicing and intervals
- Diesel Generator Repairs When maintenance finds a fault
- Generator Maintenance Ongoing readiness
- Generator Servicing The scheduled service visit
- Diesel Servicing & Maintenance The diesel service visit, booked to suit you
- Service Intervals What each level of service includes
- Load Testing Guide What a loaded test proves
- Service Checklist The general service list
- Industrial Generator Repairs Breakdowns on larger diesel plant
- Industrial Servicing & Maintenance Large diesel plant on a running-hours programme
- Contaminated Diesel Water, sludge and diesel bug
Common Questions
Questions about diesel generator maintenance
What should be on a diesel generator maintenance checklist?
Typically daily checks of oil, coolant, the air cleaner indicator, belts and the water separator; draining water from the fuel tank every 50 hours or weekly; and a minor service every 500 hours, as Perkins publishes. Your engine manual gives the exact list.
How often should a diesel generator be maintained?
Daily checks, a fuel-tank water drain every 50 hours or weekly, and a minor service every 500 hours on Perkins engines. In continuous emergency use, FEMA course material puts the oil and filter change at every 240 hours. Your engine manual sets the exact figures.
How is this different from the general service checklist?
The general checklist covers what any service visit includes. This one adds the diesel work: water in the fuel, the separator, injector symptoms and keeping a standby diesel ready between visits.
What can I check myself?
With the engine stopped and cool: levels, obvious leaks and any alarm on the controller. Leave the cooling cap closed on a warm engine, and leave the fuel-injection system to us.
How do I deal with water in the fuel?
Drain the water separator bowl and the tank drain where they are fitted, with the engine stopped and cool. If you find a lot of water or a dark slime, call us, because that points to diesel bug in the tank.
Does maintenance include injector replacement?
No. We report rough running or smoke, diagnose the cause and quote injector work separately if it is needed. Diesel injector replacement is R3,000 – R9,000 on our cost guide.
Is a load bank test part of maintenance?
We book it when you need proof that the set can carry a defined load, or when a diesel runs at light load most of the time. It is a separate visit from the oil and filter service.
What should I record?
The hour reading, the date, any alarm and any water drained. Those four make the next interval and the next diagnosis much easier.
Still unsure what the fault is? Call or WhatsApp 082 057 4605 for onsite diagnosis.
Service Areas
Onsite visits across Gauteng
We come to your generator anywhere in Gauteng, 24/7. Choose your region for local suburbs, call-out details and the faults we see most there.
What to send before we attend
These details help us plan the visit and bring the right parts. Send what you can on WhatsApp; if you can’t find the model number, we still book the visit.
- Location
- The suburb or site, so the visit can be booked in the right area.
- Make and model
- The generator brand and model, if they are known.
- kVA
- The size printed on the data plate.
- Fuel type
- Diesel, petrol, LPG, natural gas, or dual-fuel.
- Controller model
- The module name on the panel, when it is visible.
- Fault or alarm
- What the set does, and any text on the screen.
- Photos
- The generator, the data plate, and the controller or alarm. Send these on WhatsApp.
Book a Visit
Book diesel maintenance
Send the kVA, the hour reading and whether the set is standby or runs most days.
- Call
- 082 057 4605
- Message us on WhatsApp
What happens next
- We reply with questions about the generator, or to book a visit.
- A technician comes to you. For a breakdown we arrive within 1 hour.
- The fault is diagnosed on site and you get a written quote. No work starts until you accept it.
Charlie, lead technician: Degree in Mechanical Engineering, Degree in Electrical Engineering, Diesel Plant Fitter. Generator specialists since 2000.