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AUXILIARY ENGINE
REPAIR & OVERHAUL
SERVICES

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OEM-Trained Engineers
30% Faster
Turnaround Time
vs. OEM
Benchmark
30% Cost Reduction
with technology,
maintaining
reliability until the
next overhaul
Timely
Deployment
(Access to
Multiple
PRs & CDC)
Comprehensive
Support On-site,
Off-site, Remote,
including
Riding Squad
12-Month
Workmanship
Warranty
Access to Specialized
Tools such as Chris
Marine Cylinder Liner
Honing, Valve Seat
Machining Tool
Detailed
Work Completion
Report
View Reports

Introduction

Auxiliary engine services are vital for ensuring the smooth operation of a vessel’s essential systems. At Neptunus, we understand the critical role auxiliary engines play in supporting onboard electrical and mechanical functions. Our comprehensive service solutions are tailored to keep your auxiliary engines running at peak performance, enhancing overall vessel reliability and minimizing downtime.

With 3 decades of extensive service experience, Neptunus has established itself as a trusted provider of auxiliary engine repair and overhaul services. Our team of 27+ highly skilled engineers, including dedicated auxiliary engine experts, possesses a wealth of knowledge and expertise in handling various brand auxiliary engines, including Niigata (OEM Authorized), CAT (Independent Service Provider), EMD (OEM Authorized), Wartsila (Independent Service Provider), Yanmar(Independent Service Provider), MAN(Independent Service Provider), MTU(Independent Service Provider), and Detroit(Independent Service Provider). With a dedicated on-site service team and rapid response capabilities, we minimize vessel downtime and deliver quick, effective solutions, even in critical situations.

Neptunus boasts a rich portfolio of successfully completed projects, having worked on various brands of auxiliary engine services in the marine industry. We offer comprehensive auxiliary engine repair and overhaul services globally, leveraging our extensive experience in catering to clients across South Asia, the Middle East, Europe, and Africa. Our expertise extends to prominent regions within India, including Mumbai, Cochin, Goa, Kolkata, Chennai, Visakhapatnam, and Haldia. With a proven track record of delivering high-quality services, we are committed to meeting the diverse needs of our clients worldwide.

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Why choose Neptunus?

3 Decades of
Service Excellence
Engine & Propulsion
End-to-End Solutions
2500+ Successful Projects Delivered Worldwide
Trusted by 100+
Satisfied Customers
Dedicated Experts to Address Emergencies

Track Record of Job Completion on or Before Planned Timeline

Detailed Post-Service Tests and Sea-Trails to Ensure Quality

Challenges in Auxiliary Engine Repair & Overhaul Services

  • 1. Integration Challenges:
Main engine repair and overhaul involves working with auxiliary engines that are interconnected with various ship systems. Repairing one component may affect others, requiring careful coordination to ensure all systems work together seamlessly after repairs.
  • 2. Diagnostic Issues:
Identifying the exact problem with an auxiliary engine can be challenging. Since these engines power various systems, a malfunction could stem from multiple sources. Thorough diagnostic procedures and testing, as part of Diesel Engine Repairs, are required to pinpoint the issue accurately.
  • 3. Downtime Costs:
When an auxiliary engine is down for repairs, it can mean a loss of productivity or even a safety hazard. This puts pressure on technicians to complete repairs quickly, which can lead to mistakes. Efficient repair service for auxillary engine, marine engine, Generator Repair processes help minimize downtime while ensuring quality.
  • 4. Part Availability:
Finding replacement parts for auxiliary engines, especially older models, can be difficult and time-consuming. There may not be a large stock of spare parts on hand, and ordering them can lead to delays. Partnering with reliable auxillary engine repair service providers can help secure the necessary parts faster and reduce lead times.

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Process of Auxiliary Engine Overhauls

1. Preparation and Pre-Disassembly

  • Reviewing the Job Order:
We begin by thoroughly reviewing the job order, understanding the reported issues, and referencing the engine’s technical manual. This equips us with the necessary knowledge and procedures.
  • Safety First:
We conduct a safety briefing, ensuring everyone understands the hazards involved and dons the appropriate Personal Protective Equipment (PPE) like gloves, safety glasses, and steel-toed boots.
  • Isolating and Lockout/Tagout:
We isolate the engine from its fuel, electrical, and cooling systems. We then implement a Lockout/Tagout procedure to prevent accidental energization or startup.
  • External Inspection and Documentation:
We give the engine a thorough visual examination, documenting any external damages, leaks, or loose components. Photos are often taken for reference during reassembly.

2. Disassembly

  • Draining Fluids:
We drain the engine oil, coolant, and fuel into designated containers for proper disposal. Oil samples might be taken for analysis to identify wear patterns.
  • Peripheral Removal:
We systematically remove all peripheral components like the radiator, air intake system, exhaust manifold, and alternator. These are tagged and stored securely.
  • Top-End Disassembly:
We move on to the top-end by removing the valve cover, rocker arms, and pushrods. This exposes the cylinder head for further disassembly.
  • Cylinder Head Removal:
Following the manufacturer’s instructions, we carefully remove the cylinder head bolts and lift the head off the engine block. Gaskets and any sticking components are addressed meticulously.

3. Cleaning and Inspection

  • Degreasing and Cleaning:
All disassembled components are thoroughly degreased and cleaned using appropriate solvents and parts washers. This allows for a clear inspection of their condition.
  • Detailed Inspection:
Each component undergoes a meticulous inspection. We check for wear on pistons, rings, bearings, and cylinder liners. Cracks or deformations are diligently looked for. The service manual’s specifications guide our assessment.
  • Measurements and Gauging:
We use precision measuring tools and gauges to assess clearances, wear, and tolerances of critical components. This helps determine if parts need replacement or reconditioning.

4. Overhaul and Reassembly

  • Replacement or Repair:
Based on the inspection results, we replace worn-out components with new parts or recondition salvageable ones within manufacturer’s specifications.
  • Honing and Machining:
If necessary, the cylinder liners might be honed to restore proper surface finish. Certain components, like crankshafts might require machining for rectification.
  • Gasket and Seal Replacement:
All old gaskets and seals are replaced with new ones to ensure proper sealing and prevent leaks upon reassembly.
  • Reassembly Sequence:
Following the service manual in reverse order, we reassemble the engine. Torque specifications are strictly adhered to for proper fit and function.

5. Finalization and Testing

  • Reinstallation of Peripherals:
All previously removed peripheral components like the radiator, exhaust system, and alternator are reinstalled and secured.
  • Filling Fluids and Initial Checks:
Fresh engine oil, coolant, and fuel are added following the manufacturer’s recommended capacities. We perform initial checks for leaks and proper fluid circulation.
  • Electrical System Reconnection:
The engine’s electrical system is carefully reconnected, ensuring all connections are secure and free of damage.
  • Engine Start-up and Testing:
We follow the manufacturer’s starting procedures and cautiously crank the engine. Once running, we meticulously monitor oil pressure, coolant temperature, and exhaust emissions to ensure proper operation.
  • Final Adjustments and Documentation:
Any minor adjustments are made for optimal performance. All replaced parts, measurements, and observations are documented for future reference.
  • Handover and Documentation:
The engine is handed back over to the client, with a detailed report outlining the work performed, replaced parts, and any recommendations for future maintenance.

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Marine Engine Brands For Which We Provide Repair & Overhaul Service

Niigata Engine Repair and Overhaul Services
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EMD Engine Repair and Overhaul Services
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CAT Engine Repair and Overhaul Services
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Yanmar Engine Repair and Overhaul Services
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Wartsila Engine Repair and Overhaul Services
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MAN Engine Repair and Overhaul Services
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MTU Engine Repair and Overhaul Services
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Technical Seminar on

Transition from

Planned Maintenance (PMS) to
Condition-Based Maintenance (CBM)

#PMS_to_CBM_forTheChange

  • Date: 13th February 2026
  • Time: Lunch - 13:00 hrs | Seminar - 14:00 hrs onwards
  • Venue: IRS Auditorium, Powai, Mumbai - 400072
Technical Seminar on Transition from PMS to CBM

Organised by

In association with

Leaders run on CBM. Followers wait.
Where do you stand?

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*The demo link will be shared only if a valid work or company email ID is provided.