Mercedes Diesel Engine Rebuilding – OM616, OM617, OM601, OM602, OM603, OM604, OM605 & OM606

Professional rebuilding and overhaul of classic Mercedes-Benz diesel engines

Einspritzpumpen Manufaktur NRW specializes in the professional rebuilding, overhaul and mechanical restoration of classic Mercedes-Benz diesel engines.

Our workshop provides engine rebuilding services for the Mercedes-Benz diesel engine families:

OM616, OM617, OM601, OM602, OM603, OM604, OM605 and OM606.

These engines are known worldwide for their durability, mechanical quality and long service life. Today, however, many of them have accumulated several hundred thousand kilometres or have been in service for decades.

Oil consumption, reduced compression, bearing wear, cylinder wear, damaged cylinder heads or previous incorrect repairs can make a complete engine overhaul necessary.

Instead of simply replacing individual components, we inspect and rebuild the engine according to its actual technical condition.

Our focus is on precision machining, correct component clearances, professional assembly and the interaction between the engine and its diesel injection system.

Mercedes-Benz diesel engine overhaul – more than replacing parts

A proper engine rebuild begins with measurement and inspection.

Installing new pistons, bearings or piston rings into worn or incorrectly machined components does not constitute a professional engine overhaul.

Before rebuilding an engine, all relevant components must be inspected and measured.

Depending on the engine and its condition, our work can include:

• complete engine disassembly

• cleaning of engine components

• dimensional inspection of the cylinder block

• cylinder measurement

• cylinder boring

• cylinder honing

• inspection of pistons and piston clearances

• crankshaft inspection

• measurement of main and connecting rod journals

• inspection of main bearing bores

• connecting rod inspection

• cylinder head inspection

• cylinder head resurfacing

• valve and valve seat machining

• valve guide inspection

• replacement of worn engine components

• inspection of the lubrication system

• inspection of the cooling-related engine components

• precise engine assembly

• adjustment and inspection of the mechanical diesel injection system

The exact scope of work depends on the condition of the engine.

We do not replace components unnecessarily. Components that remain within specification and are technically suitable for continued use can be retained where appropriate.

Complete engine inspection before rebuilding

Every engine tells its own story.

Before deciding how an engine should be rebuilt, we determine its actual condition.

Wear patterns can provide important information about previous operating conditions.

Examples include:

• excessive cylinder wear

• tapered or oval cylinders

• piston seizure marks

• damaged piston ring grooves

• worn crankshaft journals

• bearing damage

• insufficient lubrication

• overheating damage

• cylinder head distortion

• valve seat damage

• cracked or damaged engine components

Identifying the cause of a failure is important.

Simply replacing the damaged component without understanding why it failed can result in the same problem occurring again.

Cylinder block machining

The cylinder block forms the mechanical foundation of the engine.

During an overhaul, the cylinder bores are measured for:

• diameter

• taper

• ovality

• surface condition

• wear

Depending on the measured condition, different repair methods may be required.

These can include:

• honing

• boring to an oversize dimension

• preparation for suitable oversize pistons

• additional machining depending on engine type and damage

Correct piston-to-cylinder clearance is critical.

Too little clearance can result in excessive friction or piston seizure.

Too much clearance can cause increased oil consumption, piston noise and reduced cylinder sealing.

For this reason, cylinder machining is carried out according to the dimensions of the components that will actually be installed.

Cylinder honing and running surface preparation

The condition of the cylinder surface has a significant influence on piston ring operation.

A correctly machined cylinder surface must provide suitable conditions for:

• piston ring seating

• lubrication

• oil retention

• cylinder sealing

• low wear

Honing is therefore not simply a cosmetic finishing operation.

The final cylinder geometry and surface condition must match the piston and piston ring system being used.

This is particularly important during the rebuild of older Mercedes diesel engines, where previous repairs may already have altered the original cylinder dimensions.

Pistons, piston rings and piston clearance

Pistons operate under high mechanical and thermal loads.

During an engine overhaul, pistons are inspected for condition and suitability for further use.

Depending on the engine and condition, we inspect areas such as:

• piston diameter

• piston skirt condition

• piston ring grooves

• piston crown

• piston pin bores

• piston pins

• piston rings

The required repair strategy depends on cylinder condition and available replacement components.

If cylinders require machining to an oversize dimension, corresponding pistons must be selected and the block machined to suit the actual piston dimensions.

Crankshaft inspection and measurement

The crankshaft is one of the most important components of the engine.

During rebuilding, the crankshaft is inspected and measured at the relevant bearing journals.

We examine the condition of:

• main bearing journals

• connecting rod journals

• bearing surfaces

• crankshaft geometry

• visible damage or abnormal wear

Bearing damage is not always caused by the bearing itself.

Possible causes can include:

• insufficient oil supply

• contamination

• incorrect bearing clearance

• previous incorrect assembly

• crankshaft wear

• overheating

• excessive engine loading

For this reason, crankshaft and bearing condition must always be considered together.

Main bearings and connecting rod bearings

The crankshaft operates on a hydrodynamic oil film.

Correct bearing clearance is therefore essential for reliable operation.

During engine rebuilding, the condition of the bearing journals and associated components is inspected before new bearings are installed.

The interaction between:

• crankshaft diameter

• bearing dimensions

• bearing clearance

• engine oil

• oil pressure

• oil temperature

is fundamental to engine reliability.

Simply fitting new bearing shells to a worn crankshaft is not a professional repair.

Connecting rods

Connecting rods transfer combustion forces from the piston to the crankshaft.

Depending on the engine condition and type of failure, connecting rods can be inspected for:

• visible damage

• bearing bore condition

• piston pin area

• abnormal wear

• dimensional accuracy where required

For standard engine rebuilding we aim to restore the original mechanical function of the engine.

For special performance-oriented OM603 and OM606 projects, reinforced or specially developed connecting rods can also form part of an individual engine concept.

Mercedes diesel cylinder head rebuilding

The cylinder head is another critical component during engine rebuilding.

Years of operation, overheating or valve wear can lead to problems such as:

• damaged valve seats

• worn valve guides

• leaking valves

• warped sealing surfaces

• combustion-related damage

• cooling-related damage

Depending on the engine and condition, cylinder head work can include:

• cleaning

• inspection

• measurement

• resurfacing

• valve inspection

• valve seat machining

• valve guide inspection

• replacement of worn valves

• inspection of the valve train

The objective is to restore correct sealing and reliable valve operation.

Valve seats and valve sealing

A diesel engine requires good cylinder sealing to generate sufficient compression.

Poor valve sealing can result in:

• reduced compression

• difficult starting

• uneven engine operation

• reduced engine performance

• increased exhaust smoke

Correct valve seat machining therefore plays an important role during cylinder head rebuilding.

The contact between valve and valve seat must be accurately restored.

Engine lubrication system

A rebuilt engine can only operate reliably if its lubrication system functions correctly.

During appropriate overhaul projects, oil-related components and oil passages are inspected according to the engine condition.

Particular attention is paid to indications of previous lubrication problems.

These can include:

• damaged bearings

• scored crankshaft journals

• camshaft wear

• abnormal component discoloration

• deposits or contamination

The cause of lubrication-related damage should be identified before the engine is returned to service.

Timing system and valve train

Depending on engine type, the timing system and valve train contain several wear components.

During a complete engine rebuild, their condition should be considered as part of the overall engine assessment.

Depending on the engine family, this can include components associated with:

• timing chain

• chain guides

• tensioning system

• camshaft

• valve actuation

• sprockets

The exact configuration varies between the different Mercedes diesel engine generations.

Mechanical diesel injection – one of our core competencies

A rebuilt diesel engine requires a correctly functioning fuel injection system.

This is particularly important with classic Mercedes-Benz diesel engines using mechanical Bosch injection pumps.

The engine and injection pump must work together correctly.

As specialists in mechanical diesel injection systems, we can combine engine rebuilding and injection pump service within one technical environment.

Depending on the engine and project, services can include:

• injection pump inspection

• injection pump overhaul

• calibration

• adjustment of delivery quantities

• inspection of injectors

• injector testing

• injector overhaul

• replacement of injector nozzles where required

• adjustment of opening pressures

This is a significant advantage when diagnosing older Mercedes diesel engines.

An engine problem is not always an engine problem.

Poor starting, smoke, low power or rough running can also originate from the injection pump or injectors.

Mercedes OM616 engine rebuilding

The Mercedes-Benz OM616 is one of the classic four-cylinder diesel engines used in numerous Mercedes vehicles and utility applications.

Its robust mechanical construction has allowed many OM616 engines to remain in operation for decades.

However, age and high mileage can lead to:

• reduced compression

• increased oil consumption

• cylinder wear

• bearing wear

• valve and cylinder head wear

• injection system problems

We provide mechanical inspection and rebuilding services for OM616 engines according to their actual condition.

Applications can include classic Mercedes passenger vehicles, commercial vehicles and special applications.

Mercedes OM617 engine rebuilding

The Mercedes-Benz OM617 five-cylinder diesel engine is one of the most internationally recognised Mercedes diesel engines.

Naturally aspirated and turbocharged versions have been used in numerous vehicles and today remain popular in classic vehicles, off-road conversions and special projects.

We offer professional OM617 engine rebuild and overhaul services.

Depending on condition, the rebuild can include:

• cylinder machining

• piston and piston ring work

• crankshaft inspection

• bearing replacement

• connecting rod inspection

• cylinder head rebuilding

• valve work

• complete engine assembly

• Bosch mechanical injection pump service

• injector testing and overhaul

An OM617 rebuild is always based on measurement rather than assumption.

Mercedes OM601 engine rebuilding

The Mercedes OM601 represents a newer generation of compact Mercedes diesel engines.

Despite its reputation for durability, high-mileage engines can require significant mechanical restoration.

Typical overhaul work may involve:

• cylinder inspection

• piston and ring inspection

• crankshaft and bearings

• cylinder head work

• valve components

• timing components

• injection system inspection

We rebuild OM601 engines according to their individual condition and intended future use.

Mercedes OM602 engine rebuilding

The OM602 five-cylinder diesel engine was produced in numerous naturally aspirated and turbocharged versions and is used in passenger cars, vans, off-road vehicles and special applications.

Its strong basic construction also makes it popular for individual engine projects.

We provide OM602 engine overhaul and rebuilding, including mechanical machining and injection system service.

Possible work includes:

• complete engine disassembly

• cylinder measurement

• boring and honing

• piston inspection or replacement

• crankshaft measurement

• bearing work

• cylinder head rebuilding

• valve and valve seat machining

• complete assembly

• mechanical injection pump overhaul and calibration

• injector service

Performance-oriented OM602 projects can also be assessed individually.

Mercedes OM603 engine rebuilding

The Mercedes OM603 six-cylinder diesel engine is used in a wide variety of Mercedes-Benz vehicles and is also an important platform for classic diesel performance projects.

We rebuild naturally aspirated and turbocharged OM603 engines according to their individual technical condition.

Special attention is paid to:

• cylinder condition

• cylinder head condition

• crankshaft and bearing wear

• piston condition

• valve train

• lubrication system

• cooling-related damage

• mechanical fuel injection

For special applications, we can also combine the OM603 with reinforced engine components and individually configured injection systems.

Mercedes OM604 engine rebuilding

The OM604 introduced a more modern multi-valve cylinder head concept into the Mercedes passenger car diesel range.

Professional rebuilding requires precise attention to the relationship between cylinder block, cylinder head and valve train.

Depending on engine condition, our OM604 rebuilding services can include:

• engine disassembly

• cylinder block measurement

• cylinder machining

• piston inspection

• crankshaft and bearing inspection

• cylinder head work

• valve and valve seat machining

• timing system inspection

• engine assembly

The engine is rebuilt according to measured wear and the required repair specification.

Mercedes OM605 engine rebuilding

The Mercedes OM605 five-cylinder 20-valve diesel engine combines robust mechanical architecture with excellent potential for both original restoration and performance applications.

We provide professional OM605 engine rebuilding and overhaul.

For original engines, the objective can be the restoration of correct factory-like mechanical operation.

For special projects, additional modifications can be considered according to the intended use.

Our work can include:

• cylinder block machining

• piston and ring work

• crankshaft inspection

• bearing inspection

• cylinder head rebuilding

• valve train inspection

• mechanical engine assembly

• injection system work

• turbocharger-related engine configuration

Mercedes OM606 engine rebuilding

The Mercedes-Benz OM606 six-cylinder 24-valve diesel engine has become one of the most popular Mercedes diesel engines worldwide.

It is valued both as a durable original engine and as a basis for high-performance diesel projects.

We offer complete OM606 engine rebuild and overhaul services.

Depending on the engine condition and project, our work can include:

• complete engine disassembly

• cleaning and inspection

• cylinder block measurement

• cylinder boring

• cylinder honing

• piston and piston ring work

• crankshaft inspection

• main and connecting rod bearing work

• connecting rod inspection

• cylinder head rebuilding

• valve and valve seat machining

• timing system inspection

• lubrication system inspection

• complete engine assembly

We also specialize in mechanical injection pump configurations for OM606 applications.

This means we can combine the mechanical engine build with the fuel system required for the intended application.

OM606 performance and special engine projects

In addition to standard OM606 rebuilding, we also work with individually configured high-performance engines.

Depending on the project, this can involve:

• reinforced internal components

• special connecting rods

• modified engine geometry

• individual pistons

• mechanical Bosch inline injection pumps

• turbocharger matching

• engine monitoring

• data logging

• custom engine concepts

One example is our OM606 D35 LA, a specially developed approximately 3.5-litre version based on the Mercedes OM606.

For these engines, the objective is not only maximum peak horsepower but also strong torque development and an engine configuration matched to the vehicle and intended use.

Original restoration or individual engine configuration

Not every Mercedes diesel engine needs to become a performance engine.

For many customers, maintaining the original characteristics of the vehicle is the priority.

We therefore distinguish between different types of engine projects.

Original-style engine rebuild

Suitable for:

• classic Mercedes-Benz vehicles

• restored vehicles

• collectors

• original daily drivers

• vehicles where factory-like characteristics are desired

The aim is to rebuild the engine as closely as reasonably possible to its intended original function.

Optimized engine rebuild

Suitable for customers who want to improve specific areas while retaining the fundamental engine concept.

Possible objectives include:

• improved reliability

• improved cooling

• improved injection system condition

• updated components

• moderate performance improvement

Individual performance engine

For special projects we can also develop an engine configuration based on the intended:

• horsepower

• torque

• vehicle weight

• gearbox

• turbocharger

• driving profile

• competition or road use

Mercedes G-Class diesel engine rebuilding

A particularly important application area for classic Mercedes diesel engines is the Mercedes-Benz G-Class.

Depending on model and conversion, engines from the OM617, OM602, OM603, OM605 and OM606 families can be found in or adapted for G-Class applications.

We can rebuild engines for:

• Mercedes-Benz W460

• Mercedes-Benz W461

• Mercedes-Benz W463

• expedition vehicles

• off-road vehicles

• utility vehicles

• individual diesel conversions

For heavy vehicles, engine torque and drivability are often more important than maximum peak horsepower.

The engine build should therefore match vehicle weight, transmission and intended operating conditions.

Mercedes classic cars

We also rebuild engines for classic Mercedes-Benz passenger vehicles.

Applications can include engines from vehicles such as:

• Mercedes-Benz W115

• Mercedes-Benz W123

• Mercedes-Benz W124

• Mercedes-Benz W126

• Mercedes-Benz W140

• Mercedes-Benz W201

• Mercedes-Benz W202

• other classic and youngtimer Mercedes models

The exact suitability depends on the installed engine version.

Engine rebuilding for international customers

Our engine rebuilding services are not limited to customers in Germany.

We work with private customers, workshops, vehicle specialists and companies internationally.

Engines, cylinder heads, injection pumps and other components can be sent to us for inspection and repair.

For international projects, clear identification of all components is important.

Please include information such as:

• customer name

• company name if applicable

• customer order number

• commission or project number

• engine type

• engine number where available

• vehicle or application

• description of the problem

• requested work

• contact information

For commercial customers, purchase order references and internal project numbers can be assigned to the job.

Customer-supplied engines

Customers can send complete engines or, depending on the project, individual components for inspection.

Before shipping an engine, we recommend contacting us with information about the engine and requested work.

Useful information includes:

• engine type

• engine number

• vehicle

• mileage if known

• known previous repairs

• symptoms or damage

• oil consumption

• coolant consumption

• compression results if available

• photos

• desired repair scope

This information helps us prepare the technical assessment.

Why rebuild an original Mercedes diesel engine?

For many classic Mercedes vehicles, rebuilding the original engine can be preferable to installing an unknown used engine.

A used engine may have:

• unknown mileage

• unknown maintenance history

• hidden cylinder wear

• bearing wear

• previous overheating damage

• incorrect previous repairs

A professionally rebuilt engine allows the relevant components to be inspected and measured before assembly.

It also preserves the original engine family and character of the vehicle.

For rare vehicles and international restoration projects, this can be especially important.

Repair instead of unnecessary replacement

Our approach is based on mechanical engineering rather than simply replacing complete assemblies.

Many older engine components can be inspected, measured, machined and reused if technically suitable.

Other components must be replaced because they have reached their wear limit.

The correct decision can only be made after inspection.

This is also important because replacement parts for older Mercedes diesel engines are becoming increasingly difficult to obtain.

Where necessary, we investigate alternative repair strategies and suitable replacement solutions.

Engine rebuilding and diesel injection from one workshop

The combination of engine rebuilding and mechanical diesel injection expertise is one of our key advantages.

A classic Mercedes diesel engine consists of more than the cylinder block and cylinder head.

The quality of combustion depends heavily on:

• compression

• injection timing

• injection quantity

• injection pump condition

• injector condition

• injector opening pressure

• fuel atomization

If these systems are not working together correctly, even a mechanically rebuilt engine may not operate as intended.

Our experience with Bosch mechanical injection pumps therefore allows us to assess the complete diesel system rather than treating engine and injection equipment as unrelated components.

Frequently asked questions about Mercedes diesel engine rebuilding

Which Mercedes diesel engines do you rebuild?

Our focus includes:

OM616, OM617, OM601, OM602, OM603, OM604, OM605 and OM606.

Other Mercedes diesel engine projects can be assessed individually.

Do you rebuild complete engines?

Yes.

Depending on the project and engine condition, we can carry out complete engine rebuilding from disassembly and machining through to final assembly.

Can I send my engine from another country?

Yes.

International projects are possible.

Please contact us before shipping so that the engine and project can be correctly identified and the requested work can be discussed.

Can you rebuild only the cylinder head?

Depending on the engine and condition, cylinder head repair can also be carried out separately.

The cylinder head must first be inspected to determine the required repair work.

Can you overhaul the injection pump at the same time?

Yes.

Mechanical diesel injection systems are one of our main areas of specialization.

Where appropriate, the Bosch injection pump and injectors can be inspected and rebuilt as part of the same project.

Do you rebuild OM617 engines?

Yes.

We provide rebuilding and overhaul services for Mercedes OM617 diesel engines, including mechanical engine work and injection system service.

Do you rebuild OM606 engines?

Yes.

We provide both standard OM606 engine rebuilding and individually configured OM606 performance projects.

Can you build an OM606 with a mechanical injection pump?

Yes.

Mechanical injection pump configurations for OM606 applications are one of our specialist areas.

The injection pump can be configured and calibrated according to the intended engine and vehicle application.

Do you sell exchange engines?

Availability depends on engine type and current stock.

For many projects we rebuild the customer's existing engine because this allows the exact original engine and its condition to be documented.

How much does a Mercedes diesel engine rebuild cost?

The cost depends on the engine type, condition, amount of machining required and which components must be replaced.

A reliable quotation can usually only be prepared after the engine or relevant components have been inspected.

Request a Mercedes diesel engine rebuild

For an initial technical assessment, please provide as much information as possible.

Useful details include:

• Mercedes engine type: OM616 / OM617 / OM601 / OM602 / OM603 / OM604 / OM605 / OM606

• vehicle model

• engine number if available

• mileage or operating hours

• current engine condition

• known damage

• oil consumption

• coolant consumption

• starting behaviour

• smoke or unusual noises

• previous repair history

• desired repair scope

• country of origin

Photographs of the engine and damaged components are also useful.

Mercedes Diesel Engine Rebuilding by Einspritzpumpen Manufaktur NRW

Classic Mercedes diesel engines were designed for long service lives.

After decades of operation, however, even these engines eventually require professional mechanical restoration.

Our objective is to preserve these engines through precise measurement, professional machining, correct assembly and specialist diesel injection expertise.

From the classic OM616 and OM617 to the later OM601, OM602, OM603, OM604, OM605 and OM606, we provide rebuilding solutions for customers who want to repair and preserve their Mercedes diesel engine rather than simply replace it.

Engine rebuilding, mechanical machining and diesel injection technology – combined in one specialist workshop in Germany.