How to Find Out If the Engine is the Original Block

by Leonardo R. Grabkowski,,,,

When looking at a used vehicle to purchase, it is important to know its history. Sometimes vehicle history reports and independent mechanical inspections are not enough. Find out if the vehicle has ever had the engine replaced. Since 1981 all vehicles sold in the United States have had the VIN (Vehicle Identification Number) stamped in a number of areas on the vehicle, including the engine block. Finding the stamping will help you determine if the engine in the vehicle is the original or if it has been replaced.

Step 1

Engage the vehicle's parking brake. Use the floor jack to lift the vehicle by the factory-approved front jacking point. Most jacking points are located slightly off-center under the front of the vehicle. Consult your owner's manual if you have difficulty finding it.

Step 2

Support each side of the front end with a jack stand with the side jacking mounts. The side jacking mounts are usually located about six inches behind the front wheels. They can be recognized by a notch along the bottom of the vehicle. Remove the floor jack when you have safely supported the front end.

Step 3

Get under the engine bay and use the flashlight to find the VIN. The VIN stamp location will vary from vehicle to vehicle, but it will be mounted somewhere on the engine block. Some older vehicles will contain a serial number instead of the VIN.

Match up the VIN from the engine block with the VIN of the vehicle. The VIN is best located on the lower portion of the windshield on the driver's side. If the engine block had a serial number instead of a VIN, contact a dealer for the brand to run a VIN check on your vehicle to see what serial number the original engine block had.


  • Use the flashlight to peer at all spots of the engine block. Even in direct sunlight, some areas of the engine will be dark.


  • If the VIN or serial number from the engine block does not match the VIN on the vehicle, the engine has been replaced. If you are looking at a used vehicle and the current owner denies it, they may not be lying; the engine may have been swapped before they acquired it.

Items you will need

  • floor jack
  • two jack stands
  • creeper (optional)
  • flashlight

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