Isuzu Industrial Diesel Engine Identification — Serial Number Locations Guide
Isuzu industrial diesel engines power a huge range of UK construction, agricultural, generator and marine equipment — from small mini-excavator 3-cylinder engines through to the 6-cylinder 6HK1 and 6UZ1 used in larger excavators and gensets. To order the correct service parts, gaskets, filters and components you need both the engine model and the engine serial number, and these are stamped in different locations on each engine family. This guide tells you where to look.
How an Isuzu engine number is stamped
For Isuzu industrial diesel engines:
- Engine model is cast onto the side of the cylinder block, and is also shown on the identification label found on the valve cover.
- Engine serial number is stamped on the cylinder block in a family-specific location (see the table below). Serial numbers consist of six numerical digits.
- All directional references (left, right, front, rear) are taken as viewed from the flywheel end of the engine, looking towards the front pulley.
Where to find the serial plate
The diagram below shows the typical location of the OEM identification plate on an Isuzu industrial diesel engine. Use this in combination with the model-specific serial number locations table further down.
Serial Number Location by Engine Family
The Isuzu industrial diesel reference table below gives the exact location of the stamped serial number on the cylinder block, by engine family:
| Engine family / model | Serial number location |
|---|---|
| C240 | Left front, top part of cylinder block |
| 4HK1 | Right centre, lower part of cylinder block |
| 6HK1 | Right side of cylinder block, below the injection pump |
| 6SA1 | Left rear, top part of cylinder block |
| 6SD1 | Left centre, lower part of cylinder block |
| 6UZ1 | Left centre, lower part of cylinder block |
| E120 / 6RB1 / 6WG1 | Left front, top part of cylinder block in front of the injection pump |
| All 2A & 3A | Left front, top part of cylinder block |
| All 2C & 3C | Right front, top part of cylinder block, just behind the front cover |
| All 2K & 3K | Right front, top part of cylinder block, below number-one exhaust port |
| All 3L & 4L | Right front, top part of cylinder block |
| All 3Y** | Right front, on injection pump mounting flange |
| All 4B** | Left front, lower part of cylinder block |
| All 4J** | Left rear, top part of cylinder block |
| All 6B** | Left side, lower centre of block between front engine mount and starter |
For reference, here is the original OEM diagram:
Reading directions correctly
Get the orientation wrong and you will spend an hour cleaning the wrong face of the block. The convention used by Isuzu is:
- Stand at the flywheel end of the engine.
- Look forwards towards the front pulley.
- Left is to your left hand, right to your right hand.
- Front is the pulley/timing-cover end; rear is the flywheel end.
For engines installed in machines with the flywheel at the rear of the machine (most common), this matches the operator's left and right.
What to record before ordering parts
When you are ordering Isuzu parts from us, please send:
- Engine model (e.g.
4JG1,6HK1) — from the cast lettering on the block or the identification label on the valve cover. - Engine serial number — six digits, stamped at the location given in the table above.
- Machine make, model and serial number — many spec changes are triggered by machine variant, not engine variant alone.
- The application — excavator, generator, marine, agricultural — some variants share an engine number but have different injection-pump or emissions calibrations.
Common Isuzu-powered construction equipment
Isuzu industrial diesels are fitted to a wide range of UK construction and agricultural machinery, including:
- JCB — JS and JZ series excavators (Isuzu-powered variants)
- Hitachi Construction Machinery — Zaxis ZX-series mid and large excavators
- Kubota — selected larger industrial applications
- Doosan — selected DX series
- Manitou — telehandler variants
- Selected wheel loaders, cranes and gensets across many brands
Related engine identification guides
- Perkins Engine Number Guide — country, year and family codes
- Telehandler Parts Guide — engine and powertrain components
Need help identifying or sourcing Isuzu engine parts?
Send us a clear photo of the engine plate plus the stamped serial number and we will identify the correct service parts from the parts book.
Contact us for a quote, or call 01255 323202 to speak to one of our parts team.