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ProService Generator Repairs

Diesel generator specialists

Diesel Generator Repairs Across Gauteng

Diesel generator won't start, losing power under load or shutting down on temperature? ProService Generator Repairs repairs diesel standby, commercial and industrial generators on site in Johannesburg, Pretoria and across Gauteng. We are open 24/7, arrive within 1 hour for breakdowns, and give you a written quote before work and a 1-year workmanship guarantee after it.

Call 082 057 4605WhatsApp UsRequest a Quote

Callout fee waived when you accept our written quote. 1-year workmanship guarantee. See prices

  • Standby and commercial diesels
  • Fuel, starting and cooling
  • Open 24/7, arrive within 1 hour
  • 1-year workmanship guarantee
Yellow four-cylinder diesel engine with injection pump, high-pressure fuel lines and a spin-on fuel filter

Diesel Generator Brands We Repair & Service

Choose your make to see the faults we fix most often on it, what we check and what to send before we arrive. Honda generators are petrol sets, so you will find them under Honda petrol generator repairs. Bundu Power canopied and silent diesel sets are covered on the Bundu Power generator repairs page.

Diesel Generator Sizes We Service

We work on diesel sets of every common size, from home standby units to factory installations. The size, the application, the engine, alternator and controller, the hours, the load, standby or prime duty and the service history all shape the job, so send us the kVA from the data plate and we will plan around it.

Small diesel generators

Homes, workshops, small offices and mobile or site sets. We still run a full diesel diagnosis: battery, fuel and shutdowns.

Medium diesel generators

Offices, restaurants, shops, residential complexes, schools and guest houses. These sets usually start automatically, so we test the auto start and transfer too.

Large commercial diesel generators

Office blocks, warehouses, shopping centres and larger residential developments. Cooling and transfer faults often show only when the building actually switches over, so we test under real load.

Industrial diesel generators

Factories, production sites and major backup installations. Access, fuel condition and the controller alarm shape our first hour on site.

Silent and open-skid sets

On canopy sets we check airflow and door access as well as the engine. Open-skid sets are easier to reach and get the same fuel, oil and electrical tests.

Single-phase and three-phase

We read the phase from the plate and test the output to match, and we complete electrical repairs safely on site.

Why will a diesel generator not start?

A diesel generator usually fails to start because of a flat or weak battery, loose or corroded terminals, the starter, a controller fault, an emergency stop, a low-fluid shutdown or a fuel fault. We test the battery and the panel first, because they cause most no-starts.

Why does it crank but not start?

A diesel that cranks and will not fire is usually short of fuel: a blocked filter, contaminated diesel, air in the system, a weak lift pump, injection equipment, a fuel solenoid or a control shutdown. We check the simple causes first and strip the engine only when the tests point there.

AVR, frequency, controllers and ATS

Once the engine runs, missing or unstable voltage points to the AVR, excitation, alternator, breaker or wiring. Low or high frequency follows engine speed, the governor, the load and controller sensing, and we set these on site with the right instruments. We record Deep Sea and SmartGen alarms as displayed. An ATS fault is either a start signal that never arrives or a transfer that never happens, and we test the switchgear ourselves so you never have to open it.

We assess alternator winding and insulation faults through generator rewinding, and output faults through Stamford alternator repairs and Leroy-Somer alternator repairs. Deep Sea panels are covered in Deep Sea controller repairs.

Overheating, oil pressure and load testing

High temperature can come from low coolant, a leak, a blocked radiator, a hose, a belt, the thermostat, the water pump, too much load or poor canopy airflow. If your set shuts down on low oil pressure, stop resetting it and call us, because the pressure fault may be real. Load bank testing, where the site and the set allow it, proves cooling and output under load in a way a five-minute idle cannot; our cost guide puts it at R2,800 to R5,500.

What to send before the callout

Send the generator brand, the engine brand if it differs, the model and kVA, a photo of the data plate and the controller, any alarm text, what happens when you press start (does it crank, fire, give voltage, transfer?) and your suburb. Leave out anything you do not know; we will find it on site.

Diesel generator repairs across Gauteng

The Service

Diesel standby fails differently from a petrol portable

Most backup power in Gauteng commercial buildings, warehouses and larger estates is diesel. Diesel engines are built for long loaded hours, but standby duty is a different life: long sits, short test runs, and then a sudden full load when the grid drops. That pattern produces faults that a petrol portable never sees.

Fuel is the usual weak point. Diesel that sits in a tank collects water and grows microbes. Filters clog, lift pumps lose prime and injectors wear. Your set may pass a monthly test and then fail on the first real outage, because the test never asked the fuel system to deliver at load.

Starting and cooling come next. Glow plugs and intake heaters matter on cold Highveld mornings in Pretoria and Johannesburg. Dusty radiators, tired oil coolers and blocked canopy vents cause high-temperature shutdowns only once the ATS hands the set a real building load. We trace those faults through the cooling system instead of guessing at the engine.

We repair diesel generators on site across Johannesburg, the East Rand, Sandton and the rest of Gauteng, from small residential standby diesels to commercial and industrial sets. We service and repair Cummins, Perkins, Caterpillar, Deutz, Volvo Penta, FG Wilson and Kohler generators, and we have worked on diesel plant since 2000.

Diesel set down?

Call or WhatsApp 082 057 4605. We are open 24/7 and arrive within 1 hour for diesel breakdowns across Gauteng.

Call 082 057 4605WhatsAppRequest a Quote

Diesel-Specific

Faults we see on diesel generators

  • Hard starting when cold

    We test glow plugs, heater relays, compression and the battery on standby diesels that sit for weeks between outages.

  • Fuel contamination

    Water, sludge and blocked filters build up while diesel sits in the tank. You usually find out the moment the set takes load.

  • Injector, lift-pump and injection-pump faults

    Smoke, rough running, fuel knock or a set that cranks hard but will not fire. We test the lift pump, injection pump and injectors as one system instead of swapping parts one at a time.

  • Wet stacking on light load

    Unburnt fuel builds up in the exhaust when a set never sees enough load on test. A load bank test shows the problem and helps burn it off; a longer idle makes it worse.

  • Overheating under transfer

    Some sets only run hot once the building switches over. We check the radiator, coolant and canopy airflow at the load that causes the trip.

  • Control and ATS issues

    A standby diesel is only as good as its automatic start. We diagnose controller inhibits and transfer faults alongside the engine, so one fault does not hide another.

Portable, Silent or Standby

Which kind of diesel generator do you have?

A small silent diesel and a canopy standby set share a fuel, not a fault list. The type decides what we check first.

  • Portable open-frame diesels

    Small air-cooled sets with recoil or electric start, bought for homes, sites and workshops. Air drawn in after the tank runs low and a weak battery are the usual reasons they will not start.

  • Silent air-cooled diesels

    The same small engines inside a sound-proofed case, such as the Hyundai DHY6000SE or the Kipor KDE6500T. With no radiator, they depend on clean cooling fins and clear airflow through the case.

  • Water-cooled standby canopies

    The usual set behind a larger home, an office or a complex: a water-cooled engine with a radiator, a controller and an automatic transfer switch. Battery, controller, transfer and coolant are checked together.

  • 3,000 rpm or 1,500 rpm

    Small portable and silent diesels commonly run at 3,000 rpm with a two-pole alternator; larger standby sets run at 1,500 rpm with a four-pole alternator. On either, an engine speed fault shows up as a frequency fault.

  • Air-cooled or water-cooled

    An air-cooled engine is serviced with its oil, filters and cooling fins; a water-cooled engine adds coolant, the radiator, hoses and the water pump. Some makers, such as Kirloskar, build both, so the engine plate decides.

  • Industrial and prime-power sets

    Large three-phase plant that runs for long hours or as the main supply. These are planned around shutdown windows; see our industrial generator repairs page.

How We Work

Duty, fuel and load — then the repair

  1. 01

    Identify duty and fuel

    We note whether the set runs standby or prime, check the tank and find out if the fault appears at idle or only under load.

  2. 02

    Diesel-specific checks

    We test the glow circuit, fuel pressure, filters, coolant and the air path through the canopy, and the injectors where the symptoms point there.

  3. 03

    Quote the actual repair

    You get the scope and price in writing before we start. If the tank is contaminated, the quote covers the fuel as well as the parts it damaged.

  4. 04

    Repair and loaded run

    After the repair we start the set and run it under a representative load where your site allows, so you see it working.

Fuel Type

Choose the page that matches the engine

We treat petrol and diesel as different jobs because the fuel system, the ignition and the typical size of the set all differ. A small home petrol set needs a petrol generator repair. A canopy diesel with an ATS needs the diesel work described here.

Diesel jobs more often include fuel polishing and tank cleaning, glow-plug circuits and proving the set on load. Our cost guide puts fuel system cleaning and polishing at R1,500 to R3,500. Petrol jobs more often involve carburettors, spark plugs and stale fuel in small tanks.

  • Typical diesel jobs

    Standby canopies, commercial backup, fuel and cooling

  • Typical petrol jobs

    Home portables, carburettors, spark and small tanks

  • Shared faults

    Batteries, control panels and “no output” AVRs

  • Follow-on work

    Fuel polishing and load bank testing

Common Questions

Diesel generator repair questions

What diesel generator brands do you repair?

We repair Cummins, Perkins, Caterpillar, Deutz, Volvo Penta, John Deere, FG Wilson, Olympian, Kohler, SDMO, Generac, FAW and the other diesel makes in the brand grid, each with its own repair guide.

What sizes of diesel generators do you service?

We service everything from small home standby diesels to large commercial and industrial sets, single-phase and three-phase. Send us a photo of the data plate and we will plan the visit and the parts around it.

Do you repair commercial diesel generators?

Yes. We diagnose standby sets at offices, shops, warehouses, schools and residential complexes on site across Gauteng.

Do you repair industrial generators?

Yes. We quote factory and plant-room diesel sets from the data plate, the access and the fault, and confirm the scope before we start.

Why will my diesel generator not start?

The usual causes are the battery, the starter, the fuel system, a controller shutdown or an engine protection fault. Whether the engine cranks tells us which to test first.

Why does my diesel generator crank but not start?

A diesel that cranks and will not fire usually has a fuel-delivery fault, air in the fuel, an active shutdown or an engine problem. We check the filters and bleed the air before we look at injection equipment.

Can you diagnose injector and injection-pump problems?

Yes. We investigate hard starting, smoke, uneven running and poor load response, and we test the injectors before we recommend replacing them.

Do you repair generators producing no voltage?

Yes. Once the diesel is running, we check the breaker, the AVR and the alternator to find where the voltage is lost.

Do you diagnose ATS and controller problems?

Yes. We read Deep Sea, SmartGen and other panels exactly as displayed, and we diagnose transfer faults ourselves so you never need to open live switchgear.

Do you provide preventative diesel generator maintenance?

Yes. Standby sets that rarely run still need oil, filters, coolant, battery care and a test of the start and transfer. We set the interval from your machine and its hours, and our diesel generator servicing and maintenance page sets out what each visit covers.

Do you repair diesel generators on site?

Yes. We diagnose and repair diesel generators at your premises in Gauteng, engine overhauls and major mechanical repairs included, so the set never has to be transported.

Why did my diesel start on test but fail in an outage?

Your diesel failed because a short unloaded test does not stress the fuel filters, injectors or cooling system. A real transfer runs the engine harder and longer, and that is when contaminated diesel and blocked radiators show up.

Is black smoke always injectors?

No. Black smoke can come from injectors, a dirty air filter, overload or a fuelling fault. We check the air supply and the load first, which often saves you an injection-pump repair.

What is the difference between diesel and petrol generator repairs?

Diesel sets use compression ignition, injection equipment and usually larger cooling packs. Petrol sets use spark ignition and a carburettor on a smaller frame. So even when both simply “will not start”, we begin the diagnosis in different places.

How quickly can you get to a diesel generator breakdown?

We arrive within 1 hour, 24 hours a day, 7 days a week, including weekends and public holidays. Call or WhatsApp 082 057 4605 with the suburb, the kVA and what the set is doing.

Still unsure what the fault is? Call or WhatsApp 082 057 4605 for onsite diagnosis.

Call 082 057 4605WhatsAppRequest a Quote

Related Services

Diesel faults and follow-on work

Service Areas

Diesel repairs across Gauteng

We repair diesel generators in Johannesburg, Sandton, Pretoria, Midrand, Centurion and across the East Rand, with callouts to the wider province.

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 Repair

Need a diesel generator repaired?

Tell us the kVA if you know it, the brand, and whether it is a canopy standby set or an open industrial unit.

Photos of the generator and the data plate can be sent on WhatsApp.

Add your email (optional)
  • Free written quote before any work starts
  • Callout fee waived when you accept the quote
  • 1-year workmanship guarantee

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What happens next

  1. We reply with questions about the generator, or to book a visit.
  2. A technician comes to you. For a breakdown we arrive within 1 hour.
  3. 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.