ENGINE OVERHAUL SERVICES

We provide component-level overhaul services for marine diesel engines. From disassembly and measurement to machining, testing and reporting, every stage is completed in-house at our facility in Tuzla, Istanbul.

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What Is Component-Level Overhaul?

Overhauling a diesel engine does not mean replacing the engine as a whole; it means taking each worn, deformed or out-of-tolerance component in turn and restoring it to working condition.

The advantage of this approach lies not in the cost but in the result. Every component is removed, cleaned, measured and assessed against tolerance. Parts that can be saved by machining are machined, and parts that are out of tolerance are renewed. In this way, performance close to factory values is achieved without replacing the entire engine.

At Gürfa Denizcilik, we carry out all of this work on MTU and Mitsubishi diesel engines at our Tuzla facility. Because our measuring, machining and balancing equipment is all in-house, we do not outsource the process and we control the delivery time ourselves.

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Our Working Process

01

Disassembly and Initial Assessment

The engine components are removed and an initial condition assessment is made. Which parts can be saved by machining is determined at this stage.

02

Chemical Cleaning

Soot, carbon and oil deposits are removed. Measurement only gives reliable results on a clean surface.

03

Measurement and Inspection

All components are measured. Crack, hardness and deflection checks are compared against the manufacturer's tolerances.

04

Machining and Renewal

Parts that can be brought back within tolerance are machined; refacing, line boring and balancing are applied. Out-of-tolerance parts are renewed.

05

Testing and Reporting

The relevant components are tested, assembly is completed and an overhaul report is prepared and handed over.

Our Component-Level Services

We provide overhaul services for MTU and Mitsubishi diesel engines across all of the components below.

01

Cylinder Head

Because the cylinder head forms the upper boundary of the combustion chamber, it is the component under the heaviest thermal and mechanical load. Over time it loses surface flatness, valve seating deteriorates, and cracks can form at hot spots.

Work Carried Out
  • Chemical cleaning
  • Surface refacing
  • Valve seat machining
  • Pressure testing
  • Crack testing
  • Valve, seat, guide and seal renewal
  • Complete overhaul or renewal
02

Injector

The injector determines the pressure and spray pattern at which fuel enters the combustion chamber. Tip wear first increases fuel consumption, then shows itself as incomplete combustion and a change in exhaust smoke colour.

Work Carried Out
  • Tip renewal
  • Nozzle replacement
  • Injection pressure setting
  • Leak testing
  • Spray pattern testing
  • Spare parts supply
03

Fuel Pump

The fuel pump determines the pressure and timing of the fuel delivered to the injectors. Wear in its elements leads to power loss, rough running and imbalance between cylinders.

Work Carried Out
  • Complete overhaul
  • Repair and maintenance
  • Injection setting on the test bench
  • Flow testing
  • Timing testing
  • Spare parts supply
04

Cooling System

The cooling system keeps the engine at a steady operating temperature. Salt and scale deposits in the sea water circuit, together with blockage in the heat exchanger, cause a chain of problems that leads to rising temperatures and, indirectly, to cracks in the cylinder head.

Work Carried Out
  • Sea water pump overhaul
  • Circulation pump overhaul
  • Chemical cleaning of heat exchangers
  • Rubber kit renewal
  • Leak testing
  • Flow testing
05

Block

The block is the load-bearing body of the engine. Dimensional drift in the bearing seats and surface deformation throw the crankshaft axis out of line and lead to consequent bearing damage.

Work Carried Out
  • Line boring
  • Bearing seat measurement
  • Block overhaul
  • Surface inspection
06

Crankshaft

The crankshaft converts the linear motion produced by combustion into rotary motion. Wear, deflection or cracking on the journal surfaces can lead to anything from bearing damage to the engine being put completely out of service.

Work Carried Out
  • Crack testing
  • Hardness testing
  • Deflection checks
  • Journal measurement
  • Surface assessment
07

Camshaft

The camshaft determines the opening timing of the valves and the fuel pump elements. Wear on the cam profiles and deflection in the shaft cause timing deviation and power loss.

Work Carried Out
  • Measurement
  • Deflection checks
  • Cam profile assessment
  • Bearing surface inspection
08

Piston and Connecting Rod

The piston and connecting rod are the line that transfers combustion pressure to the crankshaft. Carbon deposits on the piston crown disrupt heat transfer, while a bent rod leads to uneven wear in the liner and to oil leakage.

Work Carried Out
  • Chemical cleaning
  • Piston measurement
  • Piston crown inspection
  • Rod bend checks
  • Rod measurement
  • Rod bush renewal
09

Cylinder Liner

The cylinder liner is the running surface for the piston. When it wears, the piston rings no longer seal; oil consumption rises, compression drops and crankcase pressure increases.

Work Carried Out
  • Measurement
  • Wear and ovality checks
  • Chemical cleaning
  • Renewal
10

Oil Pump

The oil pump delivers pressurised oil to every bearing surface in the engine. Any loss of efficiency shows up directly in the oil pressure and is one of the most common causes of bearing damage.

Work Carried Out
  • Complete overhaul
  • Clearance and wear measurement
  • Renewal
  • Maintenance and testing
11

Turbocharger

The turbocharger uses the energy in the exhaust gas to deliver more air to the engine. Loss of rotor balance produces vibration, which damages the bearings and, at a later stage, leads to rotor contact and complete failure.

MTU
  • ZR140
  • ZR170
  • ZR210
Mitsubishi
  • TD-10
  • TD-13
  • TD-15
Work Carried Out
  • Complete overhaul
  • Rotor balancing
  • Welding work
  • Bearing and seal renewal
  • Spare parts supply
12

Starter Motor

The starter motor turns the main engine over for the first time. Air starter motors are widely used at sea; leaks in the compressed air system and gear wear are the most common faults.

Work Carried Out
  • Maintenance and overhaul
  • Gear and bearing inspection
  • Spare parts supply
  • Reconditioned unit supply
  • Second-hand unit supply
More about air starter motors →

In Our Own Workshop, on Our Own Machines

What determines the quality of an overhaul is not the disassembly and cleaning but the accuracy of the measurement. If the measurement is wrong, even the best workmanship produces a short-lived result.

With the measuring, machining and balancing equipment at our Tuzla facility, we complete this work under our own control, without outsourcing it. That keeps both the quality of the result and the delivery time in our hands.

Balancing machine at the Gürfa Denizcilik workshop in Tuzla
The balancing machine at our Tuzla workshop

Which Brands We Work On

MTU

We provide component-level overhaul, maintenance and spare parts service for MTU 396, 2000 and 4000 Series marine engines.

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Mitsubishi

We provide component-level overhaul, maintenance and spare parts service for Mitsubishi diesel marine engines and generators.

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Class-Compliant Work and Documented Handover

All our maintenance and repair work is carried out to standards accepted by classification societies. The work performed, the measurement results and the parts renewed are all recorded in the overhaul report.

The report is not merely a handover document. Knowing the condition of each component at the next maintenance interval lets you base your planning on data rather than guesswork.

Frequently Asked Questions

Is a complete engine replacement or an overhaul the better option?

If the main load-bearing components such as the block and crankshaft are within tolerance, an overhaul usually gives the better result. The decision is made together, based on the measurements taken after disassembly.

How long does an overhaul take?

The time depends on the size of the engine and which components fall within the scope. A firm schedule is shared once the measurement results are available.

Does the engine have to be removed from the vessel?

Not always. Components such as the cylinder head, injectors, fuel pump and turbocharger can be removed and brought to the workshop. Operations such as line boring the block, however, require the engine to be taken out completely.

Which brands do you work on?

We provide component-level overhaul services for MTU and Mitsubishi diesel engines.

Is a report provided at the end of the work?

Yes. The work performed, the measurement results and the parts renewed are all recorded in the overhaul report and handed over.

WHY Gürfa Denizcilik

Over 30 Years of Experience

More than three decades of field and workshop experience with Mitsubishi marine engines.

Original spare parts

With our extensive stock we ensure fast supply, and manufacture parts when required.

Documented Handover

We work to standards accepted by all classification societies and deliver complete overhaul reports.

In Türkiye and Worldwide

Whichever port your vessels are in, we support your operations the moment you need us. With our field service team, we provide international service for Mitsubishi (Samgong) Selfjector purifier systems.

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