There is a significant difference between REBUILT and REMANUFACTURED parts when you are considering a repair for your vehicle. Many people erroneously believe the two terms to be synonymous, where they actually refer to two different processes.

In addition, many states, such as California, require re-registering and/or re-titling of a vehicle when it has received an engine replacement, since the "facts" included in the VIN (Vehicle Identification Number) would mis-matched unless the information is corrected with the Department of Motor Vehicles.

Any part that is NOT "OEM" (Original Equipment Manufactured), falls under one of four categories:

1. NEW replacement part, non-OEM
2. USED replacement part
3. REBUILT replacement part
4. REMANUFACTURED replacement part.

Consumers should understand these categories, and their differences. While NEW and USED is rather self-explanatory, REBUILT and REMANUFACTURED are subtly different, and carry different warranties, as a rule.

According to the Automotive Parts Rebuilders Association (APRA), the "official" definition of remanufactured is, "Remanufacturing of automotive small parts, such as starters, alternators, clutches, brake calipers and wiper motors, in addition to larger parts, such as engines and transmissions begins with an inoperative, failed or worn out part called a "core". This core is disassembled so that the subsystems and components can be cleaned, tested, repaired/reworked or replaced. The components are then reassembled and tested such that the expected performance of the reassembled equipment can be defined and warranted."

Conversely, rebuilding a part is generally considered to be a simple replacement of only those components that may be broken or unusable, without a complete disassembly and inspection. As an example, a remanufactured alternator will have new diodes, new brushes, an undercutting of the armature coil, new bearings and pulleys. A rebuilt one may only have the brushes replaced.

Because of this small, but important, difference rebuilt parts generally have a much shorter warranty period (30 days to 90 days is normal), while a remanufactured unit will generally have a much longer one, such as 1-year to lifetime.

When it comes to engine replacements, it gets a bit more complicated, since the wording is almost identical. "Caveat Emptor" is the keyword here. Most quality engines will carry an AERA, ARC, or similar decal to identify that the engine has been, literally, rebuilt, using new parts, re-machining of those parts still re-usable, and rigorous testing and inspection standards. Remanufactured, when it comes to engines and engine assemblies, now has turned into a verb, meaning the part was 'Remanufactured in the USA' for example, meaning that it was rebuilt here, using primarily American sourcing for parts.

Finally, in California and some other states, -- for which you should check your state Motor Vehicle agency for details -- when replacing an engine assembly, the vehicle will need to be re-titled and registered. This is because the Vehicle Identification Number (VIN) is coded to indicate which engine that PARTICULAR vehicle has, and where it was built. The California Vehicle Code, Section 4161, states:

• (a) Whenever a motor vehicle engine or motor is installed, except temporarily, in a motor vehicle which is identified on the ownership and registration certificates by motor or engine number or by both the motor and frame numbers and subject to registration under this code, the owner of the motor vehicle shall, within 10 days thereafter, give notice to the department upon a form furnished by it containing a description of the motor vehicle engine or motor installed, including any identifying number thereon and the date of the installation. The owner of the motor vehicle shall also submit to the department with the notice the certificate of ownership and registration card covering the motor vehicle in which the motor vehicle engine or motor is installed and evidence of ownership covering the new or used motor vehicle engine or motor installed and such other documents as may be required by the department.
• (b) Upon receipt of motor vehicle engine or motor change notification and other required documents, the department shall assign a distinguishing vehicle identification number to motor vehicles, other than motorcycles or motor-driven cycles registered under a motor number or motor and frame numbers. When the distinguishing vehicle identification number is placed on the vehicle as authorized, the vehicle shall thereafter be identified by the distinguishing identification number assigned.
• (c) Notwithstanding any other provision of this section or any other provision of law, whenever an application is made to the department to register a replacement engine case for any motorcycle, the department shall request the Department of the California Highway Patrol to inspect the motorcycle to determine its proper identity. If the replacement engine case bears the same identifying numbers as the engine case being replaced, the original engine case shall be destroyed. A determination verifying proof of destruction shall be made by the Department of the California Highway Patrol.

Amended Ch. 755, Stats. 1982. Effective January 1, 1983. Amended Sec. 1, Ch. 94, Stats. 2001. Effective January 1, 2002.

The 2001 amendment added the italicized material, and at the point(s) indicated, deleted the following "the department shall not register a case for any motorcycle of the push-rod type with nonjournal rods and four-stroke engines, manufactured in the United States, without proof of the destruction of the case being replaced."

In other words, make sure to re-title a vehicle that has received an new engine. It is important.