How Long Does It Take To Replace An Engine?

Replacing an engine is no easy task. In this guide, we explain how long it takes to replace an engine and if you should rebuild or replace it.

Something that may worry many car owners is replacing an engine.

In this article, we will cover how long it takes to replace an engine and all things you should consider when doing so.

Unlike most of the repair and replacement jobs we have covered, an engine replacement needs much greater attention and work.

To be more precise, an engine replacement requires special tools and about 6-12 hours, depending on many different factors.

Let’s get into it!

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What Determines The Length Of An Engine Replacement?

car engine

Multiple factors determine the length of an engine replacement.

The greatest factor is the car model and engine layout, other factors include:

  • Engine size
  • Replacement engine
  • Availability of tools

Car Model

The car model is one of the biggest factors that determines the time it takes to replace a car engine.

Car models differ in engine accessibility. Most cars have a front engine, which is generally easier to work with compared to rear- and mid-engine cars.

Also, bigger cars, such as SUVs usually have more space around the engine, which makes it easier to navigate through the engine compartment and use the tools.

Engine Layout

Similar to different car models, a different engine layout will affect the time it takes to replace an engine.

This is mainly due to the accessibility when working with the car.

Generally, there are two types of engine layout – transverse and longitudinal.

A transverse engine layout is usually seen in front-wheel-drive cars. Their main advantage is providing more space for the engine without compromising the length of the car or the cabin.

When it comes to replacing the engine, this means that it is harder working with a transverse engine as the space in the engine compartment is more cramped.

On the other hand, a longitudinal engine layout is mostly utilized in front-engine rear-wheel-driven driven cars.

The layout compromises the cabin size, car length, or both. But unlike the transverse layout, a longitudinal layout will be easier to work with which translates to less work for a replacement.

Engine Size

car engine with hoses

The engine size plays a big role when it comes to replacing an engine. A bigger engine has more parts, bolts, and weights more.

Similarly, to the engine layout, a greater engine size means less size in the engine compartment and a tougher time dismantling every part.

Replacement Engine

It is not only the original engine that should be considered, but also the new engine.

A replacement engine does not have to be identical to the old one when it comes to displacement, power output, or even manufacturer.

However, an engine that is identical to the original engine will be easier to install. If not, many modifications must be done for the engine to fit and work properly.

Here, other systems must be considered such as the cooling, mounting, drivetrain, and more.

An engine that must be modified to fit your car will add several hours for the whole project.

Availability Of Tools

An engine replacement requires a fair amount of skill but also the right tools. While it is possible to replace an engine with a limited number of tools, the right equipment will help immensely.

Ratchet wrenches, engine hoist, impact gun, breaker bar, and many other tools make the process much easier.

DIY Versus Professional Engine Replacement

car engine

Whether it is a big or small project there is always the option to do it yourself.

As previously stated, an engine replacement requires a fair bit of skill and time. With the presumption that you are comfortable working with cars, replacing the engine yourself is plausible.

Another reason why you may consider replacing the engine yourself is the cost. Because of the time-consuming process of replacing an engine, the labor cost can be very expensive.

This applies especially if you are using an engine that was not initially designed for your car.

On the other hand, a professional car mechanic will have a good amount of experience and expertise which is welcomed as many things can go wrong when replacing an engine.

The labor cost of a professional shop will vary depending on the state, expertise, and other factors such as if it is an independent shop or a dealership.

Related:Auto Repair Labor Rate Per Hour

Should You Rebuild Or Replace An Engine?

mechanic repairing or rebuilding engine

Rebuilding an engine is cheaper in most cases, however, there are some instances where replacing the whole engine is the wiser choice.

If there is extensive damage and you can find a new engine for a good price, you should go for a replacement.

If only a few parts must be rebuilt and replaced, a rebuild is the wiser choice.

Related:How Much Does It Cost To Rebuild An Engine?


mechanic fixing or rebuilding engine

Replacing an engine can take anything from 4 to 15 hours depending on the circumstances.

In most cases, a replacement will take around 8 hours, but this depends on the car model, engine size, engine layout, and the replacement engine.

If your old engine has failed, the best alternative is to choose the same kind of engine as the install will be much easier and less time-consuming.

Replacing an engine that is not like the previous one will result in more work hours as it is very likely that several modifications must be done for the engine to fit and work properly.

Many times, rebuilding an engine is the cheaper alternative but many things can go wrong. We, therefore, recommend rebuilding an engine if the damage is not too serious.

A brand-new engine is the most reliable option but will cost more in most cases.

If done by a professional, you can expect an engine replacement to take about 6-8 hours which equals $550 to $850 in labor cost alone.

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Bajro Muric

Bajro is a big car enthusiast with a love for writing and teaching. He writes about anything regarding cars - from common problems and fixes to racing.