Generator brands · Engines
Repairs and Planned Maintenance for Large MTU-Engined Sets
We repair, service and maintain large MTU-engined generator sets on site across Gauteng, at data centres, hospitals, mines, factories and large commercial buildings. Most of the work is planned: servicing by hours and time, regular runs under load and small faults fixed before they stop the set. When something does fail, we diagnose it on site and plan the repair around your shutdown window.
Established 2006
20 years of experience
24/7 operations
We Arrive Within 1–2 Hours
(usually within 1 hour)
Free callouts and quotations
One-year warranty
Qualified and certified technicians
We Service & Repair All Generator Brands
All generator makes and models
1 kVA–20,000 kVA capability
Large engines, larger consequences
MTU builds large high-speed diesel engines and is part of Rolls-Royce Power Systems. In generator sets you are most likely to meet the Series 1600, 2000 and 4000 engines. A name such as 16V4000 reads as sixteen cylinders in a V, Series 4000, and the letters and numbers that follow describe the application and rating. Series 1600 and 2000 engines power sets from several hundred kVA to around 1,500 kVA; Series 4000 engines drive the largest sets, past 3,000 kVA at the top of the range.
These engines are turbocharged and charge-air cooled, with electronic engine management. Behind them sit operating theatres, server halls, mine pumping and airport systems, so a failure during an outage costs far more than the repair. The aim is to find faults during planned work, not during load shedding.
Large sites often run several sets, sometimes of different makes: Cummins and Caterpillar engines are common in the same size class. We check the alternator, controller and changeover equipment as well as the engine, because a sound engine is no use if the power cannot reach the load.
What planned maintenance covers on a large MTU set
| System | Typical checks |
|---|---|
| Lubrication | Typical checksOil and filters by hours or time, oil level and leaks, centrifugal or bypass filters where fitted |
| Fuel | Typical checksPrimary and secondary filters, water separators, day tank, transfer pumps and bulk tank condition |
| Air and exhaust | Typical checksAir filter restriction, turbocharger condition, charge-air pipework, exhaust leaks and back pressure |
| Cooling | Typical checksCoolant condition and additive, radiator or heat exchanger, fans and belts, jacket water heaters |
| Engine management | Typical checksLogged faults, sensor readings and protection settings |
| Starting | Typical checksBatteries, chargers and starters (some large engines have two) |
| Plant room | Typical checksVentilation louvres and dampers, attenuators, fuel and oil containment |
| Load | Typical checksA run under load to prove the set, on the building load or a load bank |
Hours or the calendar: what triggers the service
Risks on large standby sets
What catches large sets out
Jacket water heaters: Generator not starting
Standby engines are kept warm so they can take load quickly. A failed heater or its thermostat means slow, smoky starts and a set that may not take load in time.
Light-load running: Wet stacking
Large engines run on test without load build up carbon and unburnt fuel. Regular runs under real load keep them clean.
Fuel storage: Diesel fuel contamination
Bulk tanks hold fuel for months or years. Water, sludge and microbial growth build up unless the fuel is tested and managed.
Plant room ventilation: Overheating
A large set needs a great deal of cooling air. A louvre or damper that fails to open turns a healthy engine into a high-temperature shutdown.
Transfer and synchronising: Control panel repairs
On multi-set sites the sets must synchronise and share load. A controller, breaker or sensing fault can keep a healthy engine off the busbar.
Site process
How we work on a critical site
- 01
Records first
Engine and set details, running hours, service history and the controller’s event log are recorded, and the scope agreed.
- 02
Permits and a shutdown window
Inductions, permits to work and the time the set may be out of service are agreed in advance. On multi-set sites, one set is taken out at a time.
- 03
Isolate and work safely
The set is locked out against automatic starting while it is worked on. No protection is left disabled and nothing is left in manual.
- 04
Prove it under load
The set is run and loaded, on the building load where the site allows or with a load bank test.
- 05
Hand back in automatic
The set is returned to automatic, readings are recorded, and anything that needs a further shutdown is listed for planning.
Engine management, sensors and parts
MTU engines rely on electronic engine management for fuelling, speed control and protection. Many faults that look like engine failures are sensor, wiring or supply faults: a chafed harness, a corroded connector or a failing sensor can shut down an otherwise healthy engine. We trace these with the set’s controller, the engine’s own displays and meter checks on the wiring. If a fault needs the engine maker’s own software, we tell you before going further.
Parts are identified from the engine data plate and serial number, which fix the exact build. Filters, belts, hoses, sensors and service parts are genuine or quality-equivalent to the same specification, as the job and the engine allow, and long-lead parts are flagged early so they arrive before the shutdown window. See generator repairs, servicing and maintenance plans for how each visit works.
Independent service
We Service & Repair All Generator Brands
Onsite Generator Repairs is an independent generator specialist. We repair, service and maintain MTU equipment as part of our work on every make of generator.
Manufacturer warranty claims go through the manufacturer’s own network. If your generator is still under warranty, check the warranty terms before arranging work by anyone else.
Brand names and trademarks belong to their respective owners. Onsite Generator Repairs is an independent service and repair company.
Service areas
Where we work in Gauteng
FAQ
Frequently asked questions
How long can a large standby generator sit without running?
It should be test-run regularly, with periodic runs under load, and serviced by time even when the hours are low. The right routine depends on the engine’s duty and the site, and is agreed as part of a maintenance plan.
What is the difference between standby, prime and continuous ratings?
A standby rating is for mains outages, for limited hours. A prime rating is for sets that are the main power source, running long hours at varying load; a continuous rating is for constant load. The harder the duty, the lower the rating the same engine carries.
Can you load test our MTU set?
Yes. A run under real load is part of planned maintenance on a critical set. Where the building load cannot be used, a load bank test is arranged and quoted, and readings are recorded for comparison year to year.
Do you only work on the engine?
No. We Service & Repair All Generator Brands, and on a large set the alternator, AVR, controller, batteries, fuel system and transfer switchgear are checked on the same visit, because the set only works if all of them do.
What information helps before a visit?
The engine model and serial number, the set rating, recent running hours, any alarms and the date of the last service. For critical sites, tell us about access, inductions and any shutdown windows.
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Who we work for
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- We Arrive Within 1–2 Hours (usually within 1 hour)
- Free callouts and quotations