How to Buy a Used Car Engine

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How to Buy a Used Car Engine

For many people, if a car's engine fails, it is time to buy a new car. This is not necessarily the case, however, and savvy car owners know that in many cases, it is possible to buy a used car engine to replace an older one. In many cases, there is nothing wrong with these engines, they simply had the misfortune of being in a car that was damaged due to an accident, or was removed for another reason. Tracking down a used engine might be difficult, but there are auto shops and junk yards that sell them as well.

Another option for finding a used car engine is to use eBay, where sellers from many locations offer unique and obscure items. Buying a used engine can be risky, since there are few standards in place to protect buyers, but it is possible to find the right engine by keeping a few things in mind. First, it is important to determine what kind of engine is needed. Then, it is helpful to know everything possible about an engine's history. Finally, it is helpful to understand typical issues that are typically found in used engines.

Determine What Kind of Engine is Needed

Car engines all work in a similar manner, but for the most part, they are not interchangeable. This is especially true of newer cars that are extremely complicated, and have engines with delicate electronics. It is simple to say that the best replacement engine for a car is one that belonged to the same make and model car, and while this is true, there are more options. It is common for car manufacturers to use one engine type for a number of years, which allows the buyer of a used engine to search through a range of models for a useable engine. This is particularly true of classic cars made before the 1990s as engines were simpler and more interchangeable.

Ask an Expert

Even when buying a used engine online, it is helpful to consult with an expert. A mechanic or dealership can provide valuable tips and insight into the process of buying a used engine. Since it is most likely that one of these people would be helping with or performing the installation, there is no reason why they cannot be involved from the beginning.

Long Block vs. Short Block

One of the things that an expert may be able to determine is if the buyer would need a long block or a short block engine. A long block and short block can be variations on the exact same engine. The difference lies in which engine components that are included. A long block engine includes everything that should be in an engine. This means that it includes cylinder heads, camshafts, valves, valve springs and should even include an intact head gasket.

For the most part, a long block engine can be installed quickly and easily, a good replacement for an engine that is totally destroyed. A short block engine, on the other hand, is one that contains only the top part of the entire engine. A short block is designed for cases when the full engine is not in need of replacement. Buyers frequently discover that a short block engine is usually much less expensive than a long block engine.

Other Requirements

In many places, there are strict rules about a car's emissions. For this reason, it is important to look for an engine that can meet those requirements if the car is to be driven. Generally, cities have more stringent standards than do rural areas.

Learn About an Engine's History

Used engines obviously come from cars driven by people from all walks of life, but it is likely that there would be a significant difference between a car driven by a little old lady to weekly church meetings, and one used for illegal midnight drag races. For this reason, it is important to find out everything possible about an engine's history prior to purchase. In some cases, that may be as simple as asking the seller, who may be selling an engine belonging to a car that they personally owned and can provide relevant details.

In many cases, facts about a car's engine can be discovered by using an online service like Carfax. With enough information about the vehicle, buyers can pay a small fee in order to learn accident history, and if a car has a salvage title. This is also helpful in learning how many miles an engine has travelled. For the most part, the older an engine is, the farther it has travelled, and the more worn the parts of the engine are.

Salvage vs. Rebuilt Engines

In terms of used engines, there are basically two kinds available: salvaged engines and rebuilt engines. Salvaged engines are those that that have been taken as is from a car that has been in an accident, or has simply become too old to use. This is determined in some cases by the owner, or in certain countries by government regulations. This means that in many cases the salvaged engines are actually in very good condition, have only been on the road for a few years, and have been cleaned and evaluated by experts.

Salvaged engines are easier to evaluate in terms of how they might function and therefore it is easier to find out about their history. Rebuilt engines are far more difficult to evaluate. In some cases, certified technicians have carefully cleaned and restored the engine to perfect working condition. However, there are no regulations regarding what can be called a rebuilt engine, so the label can be applied to virtually any engine. Rebuilt engines with documentation from a credible source are preferable to those that are simply labelled as 'rebuilt'.

Know What Issues Are Commonly Found in Used Car Engines

For the most part, items that are made of solid metal like the engine block, the cylinder head, and the camshafts are fine in a used engine, and should seldom be a source of trouble. Simply cleaning them should eliminate any issues. One of the major sources of problems is bad compression. This means that the cylinders are not exerting enough force and that the engine may not run efficiently. A good way of determining if this might be an issue is to examine the results of a compression test. This can be done by a seller and can provide good details about an engine when the buyer does not have physical access to it. The main reason for a loss of compression lies within the head gasket. Since the head gasket separates different parts of an engine, if it is damaged or leaking, there can be serious problems with engine performance. Be aware that the cost to replace a blown head gasket is quite high.

Buying a Used Car Engine on eBay

Many buyers are surprised to discover that large items, like used car engines, are available on eBay but the truth is that there are many sellers who sell fine used engines in good working conditions. Some of these engines are from classic cars, and others are from newer models. The best way to find the right engine for you is to use the search bar on the eBay home page, or any eBay page for that matter. This search bar can use short, simple terms like, 'used car engine' or more complex ones indicating year, make, or model.

Be Thorough

This guide has already addressed the importance of learning an engine's history, but when buying one on eBay, it is important to read the product description thoroughly and to not be afraid to ask questions of the seller. Likewise, it is important to read seller feedback and selling history. Those who have good reviews and a history of selling similar items, might be better qualified to answer important questions.


For many car experts, the solution to a car with a bad engine is not to buy a new car, but to buy a new engine. Used car engines can be a less expensive way to get a car on the road, and may actually improve performance in some cases. Of course, before making such a major purchase, it is important to know specifically what kind of engine to look for. This involves knowing not only what type of engine would fit in a given car, but whether or not the complete replacement engine is needed as well. Buying a short block engine over a long block engine can save quite a bit of money in the long run.

When the proper engine is selected, it is important to know what the history of the engine is. Engines that have been rebuilt or salvaged, has their own issues most likely, but in many cases both kinds can be engines worth buying. After learning all that can be learned about the history, it is good to understand some of the basic issues found in used car engines, like whether or not the compression in sound. Keeping all of these things in mind can make it possible to buy a good engine that would restore a car to full working condition at a price that won't break the bank.

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