If you need a strong cylinder liner for diesel or industrial engines, consider the 003 WN 25 liner. It is a popular choice.

In this guide, we will go over the full 003 WN 25 specifications. We will also talk about what to look for in a cylinder liner. Finally, we will help you decide if this liner is the right choice, especially for large engines.

What Is a Cylinder Liner — And Why It Matters

Before diving into the specs, it helps to understand what a cylinder liner does and why choosing the right one matters. In an internal combustion engine, the cylinder liner is the inner wall of the cylinder. This is where the piston moves.

A well-designed liner offers a strong surface that resists wear. It also ensures good sealing and compression. Additionally, it helps with heat dissipation, especially when under heavy loads.

Using a separate cylinder liner makes maintenance and engine rebuilds easier. Worn liners can be replaced without throwing away the whole block. For industrial, marine, railway, or heavy-duty diesel engines, a good liner like 003 WN 25 is important. It can mean the difference between a long service life and needing frequent repairs.

003 WN 25 Specifications — What the Numbers Say

Here are the official specifications for the 003 WN 25 liner

Specification

Value / Description

Cylinder bore (inner diameter)

128.0 mm

Outer diameter

144.5 mm

Length (overall)

253 mm

Flange diameter

153.8 mm

Thickness

≈ 9.92 mm

Top land height

1.0 mm

Surface finish / Machining

Finished (machined, ready for installation)

Type

Wet cylinder sleeve / wet liner (outer surface designed to interface with coolant jacket)

Net weight

~ 6.64 kg

What the Specs Imply

• The 128 mm bore makes this liner good for large diesel engines. These engines are used in trucks, buses, boats, trains, and stationary power units.
• Wet liner design aids cooling. The outer surface is in coolant (water jacket). This helps the liner release combustion heat. This is important for heavy-duty or high-load engines.
• Finished machining means the liner’s inner surface is ready for the piston. This requires little extra work, which lowers the risk of a bad surface finish.
• Flange and outer diameters, along with wall thickness, help create a good fit in the engine block. This prevents leaks, misalignment, or overheating when installed correctly.

Typical Applications & Compatibility

The supplier listing for the liner cross-reference number “003 WN 25” shows its common use. This liner is often used in heavy-duty engines. It has an internal code of 89389110 under some brands.

This liner is especially common in Mercedes-Benz MK-series engines and similar industrial applications.

Vehicle Manufacturers Using the 003 WN 25 Liner

According to the parts database, this cylinder liner is commonly installed in engines used by the following commercial vehicle brands:

• Mercedes-Benz – heavy-duty trucks, buses, and transport vehicles
• Neoplan – premium long-distance buses and coaches
• Padane – European touring and transport buses
• Setra – high-capacity coaches known for long-term engine durability

These manufacturers rely on large diesel engines designed to run under continuous load. That is why a strong, wet-type cylinder liner like 003 WN 25 is suitable for them.

The cylinder liner 003 WN 25 is not for small car engines. Its size and design are made for large diesel engines. Manufacturers use these engines in trucks, buses, marine vehicles, industrial generators, railway engines, and heavy-duty stationary drives.

Also, since it has a wet-sleeve liner, it is very useful for thermal stability. This is important for efficient coolant contact in heavy loads, continuous operation, and high duty cycles.

Reference Numbers for the 003 WN 25 Cylinder Liner

The 003 WN 25 cylinder liner is listed under multiple part numbers across different manufacturers. These reference numbers help you confirm compatibility when replacing or sourcing the liner.

OEM & Manufacturer Reference Numbers

Here are the most common cross-reference codes associated with the 003 WN 25 liner:

Mercedes-Benz

• 442 011 02 10
• A 442 011 02 10
• 444 011 01 10
• A 444 011 01 10
• 444 011 02 10
• A 444 011 02 10

Mahle

• 003 WN 25

Kolbenschmidt

• 89389110

Burkert

• 20040342000
• 20040342020
• 20040342008
• 20040342099
• 20040342009

Goetze Engine

• 14-452030-00

TRW

• 2-016.119

AE

• SJ351340

GKN

• OP9063

Additional compatible numbers

• 2016.119
• 1445203000
• 4440110110
• OP9063 (duplicate listing reference)
• W4594

Read more: Ultimate Guide: Why Cylinder Liner Part Numbers Differ Across Brands

What to Check When Buying a Cylinder Liner (Buyer Guide)

Whether you’re buying 003 WN 25 or any liner — getting the right fit and ensuring reliability requires careful checking. Below are the key considerations:

1. Match bore and dimensions carefully

Make sure the engine’s piston bore matches the liner’s 128 mm inner diameter exactly. Also, check that the block’s liner-seat matches the outer diameter of 144.5 mm and the flange diameter of 153.8 mm. This ensures the liner fits tightly without leaks or misalignment.

2. Ensure liner type suits engine design — wet vs dry

003 WN 25 is a wet cylinder liner, meaning it requires a coolant jacket around the liner. If your engine block is designed for dry liners (or sleeveless casting), 003 WN 25 won’t work.

Read more: A Complete Guide to the Different Types of Cylinder Liners

3. Use correct sealing / gasket kit

For liners used in gas, marine, railway, or stationary applications, the supplier suggests using a special sealing ring set. This is especially important when using alternative fuels. Without proper sealing, coolant leaks or combustion-gas leaks can occur.

4. Inspect surface finish & machining quality

The liner's inner surface is pre-machined and finished. This reduces the risk of a poor surface finish. A poor finish can lead to excessive wear or piston ring scoring. Always inspect before installation to ensure no damage or irregularities.

5. Confirm compatibility with piston & rings

The piston diameter, piston-ring set, compression ratio, head gasket thickness, and overall engine design must match liner dimensions. A mismatch can cause compression loss, overheating, or mechanical failure.

6. Consider intended use — heavy duty, long service life

003 WN 25 is made for heavy-duty engines like trucks, buses, marine, and industrial uses. It is a good choice if your application needs strength, load-bearing ability, and long-lasting durability.

Pros and Limitations of 003 WN 25 Cylinder Liner

Pros

• Heavy-duty and ready: The 003 WN 25 liner has a 128 mm bore and strong dimensions. It is perfect for large diesel and industrial engines.
• Wet-sleeve cooling advantage: Better thermal management under heavy load or continuous duty cycles.
• Finished machining: Saves installation time and reduces risk of surface imperfections.
• Replaceable liner: You can swap out worn liners instead of replacing the whole block. This makes maintenance cheaper and easier.
• Proven compatibility: Used in engines from major OEMs (as per cross-reference codes), ensuring reliable fit and performance.

Limitations / What to Watch Out For

• Not suitable for small or medium-sized automotive engines — only for large bore / heavy-duty engines.
• You need the right sealing ring set, especially for gas, marine, railway, and alternative-fuel engines. If you skip this, it can cause leaks of coolant or combustion gas.
• Installation must be precise: wrong seating, misalignment or damage during fitment can compromise liner lifespan.
• A compatible engine block with a coolant jacket is needed for wet liner design. You cannot use it if the block does not support wet liners.

Quick Buyer Checklist: Is 003 WN 25 Right for You?

Before purchasing a 003 WN 25 cylinder sleeve / liner, go through this quick checklist:

• Is your engine a large-bore diesel or heavy-duty application (truck, bus, marine, industrial, generator)?
• Does your engine block support wet sleeve liners (coolant jacket around liner)?
• Does the piston bore match 128 mm?
• Are you ready to use a proper sealing ring / gasket set as recommended?
• Will you install the liner with care (proper seating, alignment, surface inspection)?

If you answer “yes” to all — 003 WN 25 is a solid, durable choice.

Supplier Highlight — Myron Liners

If you’re sourcing cylinder liners for your project, one reliable supplier to check is Myron Liners. They offer a range of high-quality liners suited for heavy-duty engines. You can visit their catalog here: Myron Liners – cylinder liner products

You can choose 003 WN 25 or another good liner. Myron Liners is a reliable source. They help you find genuine, well-fitted liners for your engine rebuild or maintenance work.