Can an Engine Serial Number Tell You the Year? Brand by Brand
Identification · Updated 2026-10-20
Short answer: only two of the major diesel makers put the build year inside the engine serial number, Perkins (the last letter of the engine number) and Kubota (the first character of a 7-digit serial made since June 2012). For Caterpillar, John Deere, Deutz, Yanmar, Volvo Penta and MTU, there is no public formula: the year comes from a dealer looking the serial up, or from the machine's own serial plate and paperwork.
That matters more than it sounds. People searching "Kubota serial number year" or "Perkins engine serial number list" usually want one of three things: the age of a used machine, the right parts, or proof that the engine is original. The serial does a different amount of that work for each brand.
The two that encode the year
Perkins: the final letter
A Perkins engine number looks like PJ12345U123456P, and it is three things glued together:
| Piece | Example | What it is |
|---|---|---|
| Build list | PJ12345 |
The exact application spec. This, not the 1104C-44TA model name, is what Perkins needs to pick parts. |
| Country letter | U |
Where it was built: U = United Kingdom, N = USA. |
| Serial | 123456 |
The individual engine's 6-digit sequence. |
| Year letter | P |
The year of manufacture, from Perkins' year-letter code. |
The plate is usually on the left-hand side of the cylinder block (on some series, the right). If it's gone, the same number is stamped into the block. Always quote the whole number. The build list on its own is a family, and the serial on its own is meaningless to a parts counter. Full Perkins decode →
Kubota: the first two characters (June 2012 onwards)
On Kubota engines built from June 2012, the serial is 7 digits, and the first character is the year of manufacture and the second is the month. Earlier engines used 6-digit serials without that structure.
Two traps:
- Read the block, not the sticker. The engine model and serial are stamped on the cylinder block (with a tag near the valve cover). The EPA emissions label shows a model too, and it is not the one you want.
- The tractor's serial is not the engine's. A Kubota tractor such as an M-series has its own frame serial. The engine serial dates the engine, which is usually but not always the same age. Replacement engines happen.
The ones that don't, and what to do instead
| Engine maker | Where the plate is | What the number gives you | How to get the year |
|---|---|---|---|
| Caterpillar | Serial Number Plate + Information Plate on the engine | 3-character prefix (the engine model, via Cat's prefix chart), a 5-digit sequence, plus the arrangement and performance-spec numbers | A Cat dealer or Cat SIS, by serial. Since 2001 the 8-character engine serial is the last 8 characters of the 17-character PIN. |
| John Deere | Serial plate/decal on the block or rocker cover | 13-character ESN: 2-letter plant code (CD = Saran, RG = Waterloo, T0 = Dubuque, PE = Torreón, PY = Rosario) + model (e.g. 4045T) + 6-digit sequence | Deere's model-specific serial-range charts (dealer). |
| Deutz | Identification tag, often on the valve cover (two locations on some models) | The engine model (e.g. BF4L914 = turbo, compact, 4-cyl, air-cooled, 914 family) and serial | Dealer lookup. The EPA tag on the same engine does not carry the serial. |
| Yanmar | Engine dataplate/decal | The model code (e.g. 3TNV88: 3 cylinders, TNV series, 88 mm bore) | Yanmar's distributors ask owners to send them the code. |
| Volvo Penta | Right side of the block (industrial/genset) or port side of the flywheel housing (marine) | Type designation (e.g. TAD722GE), spec number and serial | Volvo Penta service history, by serial. |
| MTU | Engine type plate | Type designation (e.g. 12V2000G65: 12 cylinders, V, Series 2000, genset application) and engine number | MTU dealer, by engine number. |
| Mitsubishi | Nameplate on the engine's front side | Model and serial together, e.g. "S16R * 10012" | Dealer lookup. |
The pattern: for these makers the serial is a lookup key, not a code. Write down every number on the plate before you call anyone. Cat dealers want the serial, arrangement and performance-spec numbers together, and Volvo Penta wants model, spec and serial.
Dating a used machine when the engine won't tell you
When the engine serial is silent, the age usually still exists elsewhere:
- The machine's own serial plate (PIN). Excavators, loaders and tractors carry a frame serial separate from the engine's. Manufacturers and dealers date machines by that number, and it's the one on the title or invoice.
- The emissions label. The EPA/EU label states the emission tier or stage the engine was certified to, which brackets the era even when it doesn't give a year.
- Component date codes. Alternators, starters, hoses and glass often carry their own date stamps. Several matching dates are good evidence that the engine and machine are original to each other.
- Service records. For any machine bought from a fleet, the dealer's history by serial is the most reliable date you'll get.
Once you've identified it
The model designation, rather than the date, decides what fits. A 1104C-44TA, a 4045T or a 3TNV88 tells you the filters, belts and service intervals; our engine pages list what the manufacturer documents give for each. When you order service parts, buy by engine model and confirm against the serial. A Perkins 1100-series filter kit or Kubota D1105 filter kit is matched to the engine, not to the machine it's bolted into.
Decode rules on this page come from the manufacturers' own identification material where they publish it (Perkins, Kubota, Caterpillar, John Deere, Volvo Penta, MTU, Mitsubishi) and from dealer cross-reference guides where they don't (Deutz, Yanmar). Each brand's linked guide names its source.