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Does Replacing A Car’s Engine Reset The Odometer?

Does Replacing A Car’s Engine Reset The Odometer?

When you replace a car’s engine, it’s a big job! But while most of your attention will be focused on what’s happening underneath the hood, you may also wonder if getting a new engine resets the car’s odometer back to zero.

Replacing a car’s engine does not reset its odometer as this reading measures the vehicle’s total mileage and not individual components such as the engine. Manipulating the odometer is illegal at both the state and federal levels.

Keep reading to learn more about why replacing a car’s engine does not reset its odometer.

What an Odometer Measures

When you and most other people initially think of an odometer, it is assumed this measures only the car’s mileage. While it does this, the odometer does much more. 

In fact, it gives an owner, mechanic, or potential buyer crucial information about other components of the car, such as its transmission, suspension, steering, brakes, differentials, and much more.

If the odometer reading is not accurate, it is not only providing a misleading representation of the vehicle itself but is also potentially throwing the vehicle’s routine maintenance checks out of whack. 

As today’s newer cars have come to rely more and more on electronic systems, an inaccurate odometer reading can lead to some crucial maintenance tasks and repairs not being made at certain times!

Should this occur, you could be looking at a car that will not get oil changes, transmission fluid changes, radiator flush and fill, or power steering fluid changes at its scheduled intervals, which could lead to engine damage and other expensive problems and repairs.

Why It’s Illegal to Reset the Odometer

If you decide to tamper with your car’s odometer, be prepared to find yourself likely getting caught and arrested by police officers. 

In all states, it is illegal to tamper with the mileage reading of any motor vehicle. In fact, it’s also prohibited by federal law as well!

According to the National Highway Traffic and Safety Administration, it is estimated that unsuspecting car buyers are cheated out of as much as $10 billion per year due to odometer fraud. 

Since doing so shows you have the intent to deceive a potential buyer, you are committing fraud should you reset the odometer and then sell the vehicle to an unsuspecting buyer.

While modern odometers have gone digital and are very easy to read on your dashboard, this has actually made them easier to manipulate! 

Believe it or not, it is not hard to go online or even look in a newspaper or magazine and find an ad from someone offering what is known as “mileage correction services,” which means you can pay them to tamper with an odometer.

However, like most things today, car mileage records are much easier to trace than in years past. 

Although an odometer may have been tampered with, the vehicle’s TCM and PCM probably were not, and both of these also contain their own records that are much harder to manipulate.

In addition, the main dealer from which a vehicle originated also keeps a complete record of all its vehicles, including their mileage. 

Whenever you take a car in for service or repairs, you may not have been aware its mileage is recorded and entered into a national database. 

With the advent of cloud computing, these mileage records are easily accessible by dealers nationwide, meaning it’s almost impossible to get away with odometer tampering.

Does Replacing the Car’s Engine Change Its Value?

When you put a new engine into a used car, it does change its value significantly, and almost always for the better!

Once a car has a new factory-made engine under its hood, it’s almost as if the car is considered to once again be brand new. By removing the original engine, you are essentially removing the wear and tear that accumulated over the years. 

As a result, the vehicle’s performance will be greatly enhanced, making it an intriguing purchase for a car buyer.

When you are looking up the value of your vehicle in Edmunds or Kelley Blue Book, you’ll quickly be able to see just how much extra value a new engine can bring to your car. 

If you had a used car that was considered to be in fair to poor condition with its original engine, placing a new engine under its hood will often elevate the vehicle’s status to good or even very good, greatly increasing its value and ultimately its selling price.

Of course, getting more money for your car after an engine replacement is contingent upon your car is in good shape in other areas, such as transmission, body, tires, and so forth. 

Thus, even after your car gets a new engine, you cannot legally represent it to a buyer as a “new” vehicle, so keep this in mind if you are looking to sell after the new engine is put into place.

As an example, if you are selling your used car, you should tell a buyer that while the car actually has 100,000 miles on its odometer, the engine currently under the hood was replaced at the 90,000-mile mark, which lets them know the new engine only has 10,000 miles worth of wear and tear.

Does the VIN Change When the Engine Gets Replaced?

When an engine actually gets replaced, the car’s VIN does in fact change. 

As you know, the VIN for your car is located on the dashboard. 

However, you probably did not know that the VIN on the dashboard also matches the serial number on your car’s original engine.

If an entirely new engine is put into your car, the serial number on the engine block will be different than the number on the dashboard. 

However, if the original engine was simply rebuilt, the VIN on the dashboard and the serial number on the engine should still match. 

If you are looking at a car to buy and these numbers don’t add up, chances are the car’s owner is misinformed or deliberately trying to mislead you about the car.

Why are Odometers Rolled Back?

The most obvious reason a car’s odometer is rolled back is to convince a buyer that they are purchasing a car that has very low mileage. However, that’s not the only reason this happens.

In some instances, a car owner will attempt to roll back their odometer so that they can take advantage of getting repairs done to their vehicle that would still be covered under its warranty, which of course could save them thousands of dollars.

In other situations, a person may tamper with their car’s odometer if they are leasing the vehicle and have driven more than anticipated, which would lead to additional mileage charges.

When odometer tampering is done on a vehicle, other steps are also often taken to make the car appear newer. 

This usually includes detailing it to remove obvious signs of wear and tear, possibly installing a new engine or rebuilding the existing engine, and other steps the seller believes will convince a buyer to pay their price.

Are Other Components Replaced When an Engine is Replaced?

When an engine is replaced in a car, it is often standard to change other components as well.

These include the water pump, spark plugs, timing belts and chains, seals, and thermostat, along with the various fluids found under the hood.

Since tampering with an odometer can land you in prison, it’s not recommended you do so under any circumstances.

By replacing your car’s engine and taking care of other maintenance tasks along the way, your car will be in great shape and ready to either be driven by you for many more years or instead sold to a buyer who knows exactly what they are getting.

Zach Reed

Hi, I'm the founder of! Having owned a wide variety of vehicles in my life, I was astounded at how hard it can be to find answers to common automotive questions. Rather than sit idly, I decided to create this website to help others!