We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Engines

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What are Rebuilt Engines?

By S. Mithra
Updated: May 23, 2024
Views: 70,087
Share

Rebuilt engines, frequently called overhauled engines, have been dismantled, inspected, cleaned, and their parts replaced or repaired to update them to current manufacturing specifications. Rebuilding an engine, while labor intensive, costs less than replacing an entire vehicle or a new engine. Due to the unique rebuilding process, some parts might be as old as the original, slightly used, or brand new, but many manufacturers will offer a warranty anyway. Choosing a rebuilt engine can extend the life of a car and might be a cost-effective option for drivers who know that they have serious engine trouble.

Technically, engines that are rebuilt are different from those that have been overhauled. With rebuilt, or remanufactured, engines, a mechanic will either save or fix parts based on the amount of wear or damage. The original manufacturer of the engine, whether from an automobile or boat, is the only one authorized to remanufacture it. Much specialized machining is done to ensure that every part works well. Overhauled engines, however, contain only a few replaced parts, at full cost, and rarely involve machining old parts. This can be less effective in extending the life of the vehicle.

Some of the machining done in the rebuilding process includes reforming the piston-cylinder system. The cylinder channels are re-bored and the pistons are fitted to match the larger cylinders. All bearings are smoothed and lubricated. The crankshaft or camshaft might be reground, heads resurfaced, and connecting rods machined and precisely gauged. Other less expensive parts, such as the timing belt, gaskets, and belts, could be replaced.

Since rebuilt engines have different parts with different operating histories, they are not guaranteed to last as long as a new engine. A part that was fine when the engine was evaluated during the remanufacturing process may malfunction after the engine has been re-installed. The engine has been thoroughly inspected, however. When a mechanic rebuilds an engine, he or she may be able to find other, previously undiagnosed issues that can be fixed before they cause problems.

Another advantage is that the engine will meet the requirements for original equipment manufacturer (OEM) specifications. These might have changed since the engine was first produced, and their improvements might make it run smoother and more efficiently.

Share
WikiMotors is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
By anon284154 — On Aug 08, 2012

@Desiree16m: Resetting the miles on your car is illegal in most states, although mechanics can make this happen for you.

By anon283425 — On Aug 04, 2012

@desiree: I'd think the answer would be no. I've seen people say "The engine was rebuilt at 120k miles" in an ad.

As far as parts go, bike bandit is excellent for motorcycles.

By MrSmirnov — On May 04, 2011

For someone who is new to rebuilding car engines, what are some tips you would give when choosing used parts?

By letshearit — On May 02, 2011

I agree that rebuilding an engine can be a really cost-effective option when doing repairs. My father used to take me with him to the local scrap yard to help choose parts when he worked on rebuilding his car. There are perfectly good parts there that you can get very cheaply.

Nowadays, if you know what part you need, there are sites that specialize in finding you the piece from a junkyard and having it sent to you. A great bargain indeed!

By desiree16m — On Feb 12, 2009

when you put a rebuilt engine in your car do you reset your miles on the car or does it give you any more miles at all?

Share
https://www.wikimotors.org/what-are-rebuilt-engines.htm
Copy this link
WikiMotors, in your inbox

Our latest articles, guides, and more, delivered daily.

WikiMotors, in your inbox

Our latest articles, guides, and more, delivered daily.