Where Is the Engine Number on a Car? (VIN vs Engine Code Explained)
Need to know exactly which engine is in your car before ordering a replacement? This guide shows you where to find the engine number on Hyundai, Kia and most other cars sold in Australia, how to decode it, and why suppliers ask for it.
Where is the engine number on a car?
The engine number is stamped directly into the engine block, usually on a flat machined pad where the engine meets the transmission. On most Hyundai and Kia engines it sits at the front of the block below the cylinder head. It is also printed on your registration papers in most Australian states.
Is the engine number the same as the VIN?
No. The VIN (Vehicle Identification Number) is a 17-character code identifying the whole vehicle, found at the base of the windscreen and on the build plate. The engine number identifies the engine itself and changes if the engine is ever replaced. Australian registration records list both, which is why rego papers are the fastest place to check.
How do I find the engine code on a Hyundai or Kia?
Hyundai and Kia use a shared coding system. The first letter tells you the fuel type: G for petrol (gasoline) or D for diesel. The second character is the cylinder count, and the remaining letters identify the engine family. So a G4KJ is a 4-cylinder petrol engine (the 2.4L GDI used in the Kia Optima and Hyundai i45), while a D4HB is a 4-cylinder diesel (the 2.2L CRDi used in the Santa Fe, Sorento and Carnival).
| Where to look | What you will find |
|---|---|
| Registration papers | Engine number and VIN as recorded with your state authority |
| Engine block (machined pad) | Stamped engine number starting with the engine code, e.g. G4KJ… |
| VIN plate / windscreen | 17-character VIN — characters identify model, plant and year |
| Owner’s manual specs page | Engine family and capacity for your exact variant |
Can I tell what engine is in my car from the VIN?
Partly. The VIN encodes the engine variant fitted at the factory — a Hyundai or Kia dealer, or any state rego-check service, can decode it for you. But if the car has ever had an engine swap, the VIN will not reflect it. That is why reputable engine suppliers verify against both the VIN and the number stamped on the engine itself.
Why do engine suppliers ask for my VIN or engine number?
Because “one engine per model” is a myth. A single model like the Hyundai i30 was sold in Australia with G4NB, G4NC and G4FJ engines depending on year and trim. Ordering by model name alone risks an expensive mismatch. When you send us your VIN, we confirm the exact engine family, year band and ancillary differences before anything ships.
Frequently asked questions
What does the G in Hyundai engine codes mean?
G stands for gasoline (petrol). D stands for diesel. The digit after it is the number of cylinders.
My engine number does not match my rego papers. Is that a problem?
It usually means the engine was replaced at some point. In most states you must notify the registration authority after an engine change so records stay accurate — your mechanic or the transport department can guide you through it.
Do I need the engine number to buy a replacement engine?
The VIN is usually enough for us to identify the correct engine family, but having the stamped engine number as well removes all doubt — especially on older cars that may have had a previous swap.
Ready to match an engine to your car? Browse brand-new crate engines for petrol and diesel applications, or send us your VIN and we will do the checking for you.