Power & performance analysis
We verify with measured data whether your set can carry the full critical load — chillers, lifts, kitchens, server halls — when it matters.
Emergency response within 24 hours
On-site heavy maintenance & overhaul · 500 kVA – 4 MW+
Complete overhaul,in your engine room.
We overhaul high-power diesel and gas generators where they stand — in your engine room, without dismantling the set or shipping it to a workshop. OEM procedures, OEM parts and a full load-bank test before handover.
24h
Emergency response
9–12days
Complete overhaul incl. commissioning
100%
Load-bank tested before handover
7
Major OEM engine platforms
Engine platforms we overhaul
MTU, Cummins, Caterpillar, Perkins, Doosan, MWM, Jenbacher Brand names are trademarks of their respective owners. ONCORE is an independent service provider.
⚡GRID FAIL · 00:00:03 · ATS → GEN
Why it matters
A generator is only as good as its worst day.
Picture the busiest night of the season: every room is occupied, the grid fails — and the standby set does not take the load. Air conditioning stops, kitchens go silent, guests are trapped in lifts and the reviews start before the lights come back.
For hospitals, data centres, mines and industrial plants, an outage is not an inconvenience — it is simply not acceptable. Visual inspections and filter changes cannot tell you how an engine will behave when it is hit with 100% load in a single step.
RevenueLost turnover and penalty clauses from every hour of downtime.
ReputationOne blackout can undo years of reviews and client trust.
SafetyCritical loads — ICU, servers, ventilation, lifts — lose protection.
What we do
Beyond routine maintenance: we look inside the engine.
Our engineers do not just check whether the set runs. We measure, test and rebuild it to factory condition — on site.
Internal inspection & NDT
Micro-wear, bearing and winding damage and mechanical fatigue are detected before they turn into failures, including non-destructive testing of critical parts.
On-site overhaul
Top-end, in-frame and complete overhauls (QL4, E50, E60 and equivalent levels) performed in your engine room with our mobile workshop equipment.
OEM parts & calibration
Pistons, rings, liners, bearings, valves and seals replaced with genuine OEM parts; injection systems and turbochargers calibrated and renewed.
Alternator & control systems
Winding insulation (Megger) tests, AVR and control panel checks, synchronisation and protection settings restored.
Load-bank commissioning
Stepped 25 / 50 / 75 / 100% load testing with our mobile load banks; temperature, pressure and power data documented in a handover report.
Why on site
The workshop comes to the engine — not the other way round.
Removing a multi-tonne generator set means cranes, transport, rigging, re-alignment and weeks without backup. We bring the engineers, tooling and test equipment to you instead.
Conventional workshop overhaul
ONCORE on-site overhaul
Dismantling & transport
Crane, rigging, road transport both ways
✓None — the set stays on its foundation
Typical downtime
4–8 weeks
✓9–12 days including commissioning
Temporary power
Rental generator often required
✓Usually not required
Re-installation risk
Re-alignment, cabling and piping work
✓No re-installation
Final test
Workshop test, then site test again
✓Load-bank test in its real environment
How we work
OEM procedures. Measured tolerances. Documented at every step.
Overhauling large engines demands strict adherence to manufacturer standards. Every phase follows documented OEM procedures.
01
Advanced diagnostics & disassembly
ECM fault history and operating data are analysed. Cylinder heads, turbochargers, crankshaft and bearings are dismantled according to OEM manuals.
02
Precision measurement & NDT
Liner wear and ovality, connecting rods and crankshaft are measured to the micron. Non-destructive testing reveals hairline cracks invisible to the eye.
03
OEM parts & renewal
Worn pistons, rings, main and rod bearings, valves and seals are replaced with genuine OEM parts. Fuel injection and turbochargers are calibrated.
04
Precision torque & assembly
Every component is assembled to the specified torque values and tightening sequences with digital torque wrenches. Megger tests and panel synchronisation complete the job.
05
Dynamic load test & handover
The set is tested with mobile load banks at 25, 50, 75 and 100% load. Temperature, pressure and power data are verified and the generator returns to service in zero-hour condition.
Every overhaul ends under full load.
Stepped load acceptance with our mobile load banks — no handover without verified data.
Field projects
Proven where failure is not an option.
A selection of overhauls our team has delivered on site.
Mid-season breakdown at a luxury resort
In the middle of the season two of four sets failed, leaving the resort with 50% of its standby capacity. We were on site within 24 hours and returned both units to service in nine days.
- Location
- Mediterranean · 5-star resort complex
- Equipment
- Doosan AD825 sets (Aksa 750 kVA), 4-unit plant
- Scope
- Major overhaul of 2 generators with heavy mechanical damage, parts and engineering
- Response
- 24 hours
- Duration
- 9 days, on site
Three MTU sets at a desert mine
Three 16-cylinder MTU engines powering a remote mine were fully overhauled on site in harsh desert conditions.
- Location
- Africa · open-pit mine, desert conditions
- Equipment
- 3 × MTU 16V4000 G23 generator sets
- Scope
- Complete QL4-level overhaul
- Duration
- 12 days including commissioning
Rebuilt to factory tolerances
Full E60 overhaul of a V12 biogas engine — connecting rods, liners and cylinder heads measured, renewed and reassembled to factory tolerances.
- Location
- Türkiye · biogas power plant
- Equipment
- 1 × MWM TCG 2020 V12 gas genset
- Scope
- Complete E60-level overhaul, parts and engineering
- Duration
- 9 days including commissioning
Back on line in ten days
The client had been quoted one month of downtime plus a rental generator. We were on site within 24 hours and had the set back on line in ten days.
- Location
- Türkiye · high-rise office complex
- Equipment
- 1 × Cummins KTA50-G3 generator set
- Scope
- Overheating failure — complete overhaul, parts and engineering
- Response
- 24 hours
- Duration
- 10 days including commissioning
Precision on site: E50 maintenance
Scheduled E50 maintenance on one of the largest MWM gas engine platforms, completed with full tolerance documentation.
- Location
- Türkiye · gas engine power plant
- Equipment
- MWM TCG 2032 gas engine
- Scope
- E50 periodic maintenance: pistons and liners measured and cleaned, covers serviced, seals and filters renewed, tolerance checks, test and commissioning
Full-scope E60 for green energy
A complete E60 overhaul keeping a waste-to-energy plant producing renewable power for the city.
- Location
- Türkiye · biomethanisation facility
- Equipment
- Jenbacher J420 gas engine
- Scope
- E60 overhaul: complete mechanical revision, cylinder group and valve train, turbocharger and auxiliaries, consumables and seals, performance verification
Industries
Built for sites where power is mission-critical.
Hotels & resorts
Guest comfort, kitchens, lifts and pools — protected through peak season.
Hospitals
Operating theatres and ICUs that cannot wait for the grid.
Data centres
Standby power that must start and take load within seconds.
Mining
Remote prime-power plants in the harshest environments.
Biogas & landfill gas
Gas engines running 8,000+ hours a year on renewable fuel.
Industry & manufacturing
Continuous processes where minutes of outage cost a day of output.
Marine & yachts
Auxiliary gensets serviced at berth or at the shipyard.
Commercial real estate
Towers, malls and plazas with life-safety loads.
Worldwide mobilisation
Engineers, tooling and load banks — wherever your engine is.
Headquartered in İzmir, Türkiye, we mobilise complete overhaul teams to Europe, the Middle East, Africa and Central Asia. Field projects already delivered across Türkiye and Africa.
- Dedicated project engineer from first call to handover
- Mobile workshop, lifting and precision tooling shipped with the team
- OEM parts sourcing and logistics handled for you
- Bilingual technical reports and measurement records
FAQ
Questions engineers and facility managers ask us.
Can a complete overhaul really be done without removing the generator?+
Yes. In-frame and complete overhauls of large engines are performed on the foundation. We bring lifting gear, precision tools and measuring equipment to the engine room, so there is no crane work, no transport and no re-alignment.
Which engine brands and sizes do you work on?+
We specialise in high-power diesel and gas generator sets, typically from 500 kVA to several megawatts — MTU, Cummins, Caterpillar, Perkins, Doosan, MWM and Jenbacher platforms.
Do you use original parts?+
Yes. Wear parts, bearings, seals and gaskets are genuine OEM parts, and every assembly follows the manufacturer's torque values and sequences.
How fast can you respond to a breakdown?+
For critical failures our team can be on site within 24 hours in Türkiye; international mobilisation is planned around visas and logistics, typically within a few days.
How is the work verified?+
Every overhaul ends with a stepped load-bank test at 25, 50, 75 and 100% load. You receive a report with measurements, replaced parts, torque records and test data.
Do you work outside Türkiye?+
Yes. We have delivered projects in Africa and mobilise to Europe, the Middle East and Central Asia. Contact us with the engine model and location for a mobilisation plan.
Is your standby power ready for its worst day?
Send us your engine model, running hours and location. An engineer will reply with an assessment plan.
Talk to an engineerContact
Tell us about your engine.
Share a few details and we will get back to you with a technical assessment and mobilisation plan.
Phone+90 553 640 56 98
WhatsApp+90 553 640 56 98
Emailozkan.tastan@tanitek.com.tr
HeadquartersKarşıyaka, İzmir, Türkiye