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Engine Swap 101: A Complete Guide to Swapping Engines

An In-Depth Look at What’s Involved in An Engine Swap

Swapping an engine in a vehicle is an ambitious project that can extend the life of your vehicle. Having been involved in numerous engine swap projects, I can confidently say that the process is as much about preparation and understanding as it is about turning wrenches. Whether you’re replacing a worn-out engine with a like-for-like replacement or going for a performance upgrade with a completely different engine, there are critical factors to consider. Let me walk you through what’s involved in an engine swap, the differences between swapping the same engine type versus a different one, and the associated costs.

For more information on the labor costs to perform an engine swap, see this article.

Performing an engine swap with an exact replacement engine

If you’re replacing your current engine with the same brand and size, this procedure is usually called “direct replacement.” This type of engine swap requires no modifications because the engine’s dimensions, mounting points, and wiring harnesses match perfectly.

What other services should you consider at the same time as the swap?

Whether you or the shop is buying a used, rebuilt, or new engine, the swap will require removing and refitting multiple components from the old engine. So this is the perfect time to consider the installation of new serpentine and timing belts, belt tensioners, water pump (if installing a used engine), radiator and heater hoses, spark plugs and spark plug wires (if equipped), fresh coolant, and power steering fluid. Replacing these accessories and fluids now will cost less than replacing them after the engine is installed in the vehicle.

Key Steps in a PerDirect Replacement Engine Swap

Sourcing the engine— You have three options to conduct an engine swap with a direct replacement: used engine versus rebuilt or new.

Pros of installing a used engine:

1) Lower Cost— Installing a used engine is usually

This image shows a used engine from a wrecking yard

Used engine from wrecking yard

the least expensive option for getting a working engine back into your vehicle. Used engine prices are based on market demand, mileage, and the warranty offered by the seller. The cost of a used engine varies based on the vehicle’s popularity compared to the demand. For example, Hyundai and Kia vehicles are very popular, so theoretically, there should be a large supply of used engines. However, due to the incredibly high failure rates of the Theta II, Gamma, and Nu engines, the demand for these engines is very high, driving up the cost to $2,000 – $4,000 for just the engine (not including labor).

The engine prices for other vehicles can be more reasonable. For example, a quick search for the 2007–2011 Toyota Camry 2.4L engine shows prices in the $1,200 range. A 2010–2015 Toyota Camry 2.5L engine is available for $1,695, while a 2018 Toyota Camry 2.5L engine with 108,000 miles runs about $900.

2) Availability: You can usually get a used engine within a few days or up to a week if it’s being shipped from an out-of-state wrecking yard.

Cons of installing a used engine:

1) Uncertain History— One of the biggest risks is the unknown history of the engine. It may have hidden issues, such as poor maintenance, high mileage, or prior damage, which could lead to premature failure. Auto-wrecking yards don’t have access to the engine’s maintenance history, nor do they test the engines they sell. If the engine was running when the vehicle was wrecked, the seller assumes the engine was in good working order.
2) Shorter lifespan— will have a shorter lifespan compared to a rebuilt or new engine.A used engine
3) Shorter warranty— A used engine only has a 30-90 day warranty compared to rebuilt and new engines that often carry up to a 3-year warranty.

Pros of installing a rebuilt engine:

1. Cost-Effective Compared to a New Engine
2) Improved Reliability— A rebuilt engine undergoes a comprehensive inspection and replacement of worn components, which can restore it to like-new condition. Professional rebuilding often includes upgrades to address known issues inherent in the original design.
3) Better warranty— Rebuilt engines often come with a 2-3 year warranty.

Cons of installing a rebuilt engine:

1. Higher Initial Cost— Compared to Used Engines
2. Variable Quality— The quality of a rebuilt engine depends on the expertise of the rebuilder and the parts used. Choosing an unreliable rebuilder can lead to subpar results. Some rebuilders only replace the most damaged components, leaving others vulnerable to future failure. For example, a rebuilt engine from a dealer is generally considered a much higher quality rebuild than from a local or national rebuilder.
3. Time-Consuming— The rebuilding process can take time, especially if parts need to be ordered or specialized work is required.

Pros of installing a New engine:

1. Reliability— A new engine is in pristine condition,

This image shows a rebuilt Toyota engine

This is a rebuilt long-block engine. It doesn’t come with the accessories. So, the shop must transfer over the valve covers, alternator, starter, power steering pump, AC compressor, idlers, belt tensioner, and belts.

built to factory specifications, and free from wear and tear, ensuring reliable performance and longevity. It eliminates concerns about hidden defects or past misuse often associated with used or rebuilt engines.
2. Warranty Coverage— New engines typically come with robust warranties, often ranging from 3 to 5 years, depending on the manufacturer. Some warranties also include labor coverage.
This provides peace of mind and protection against potential manufacturing defects.
3. Optimal Performance— A new engine operates at peak efficiency, offering better power output, fuel economy, and reduced emissions compared to used or rebuilt engines.
4. Maintains vehicle value— Installing a new engine maintains vehicle value more than a used or rebuilt engine.

Cons of installing a New engine:

1) Highest cost— A new engine will cost substantially more than a rebult engine
2) Availability— Some carmakers don’t sell complete engines. Toyota, for example, only sells short blocks, cylinder heads, and internal parts. The shop must assemble the components into a complete engine. In addition, the dealer will have to order the short block, heads, and internal parts, sometimes causing delays of a month or more.
3) Over-investment— Paying for a new engine can put you underwater in the event of a severe wreck where your insurance totals the vehicle.  Consider the value of the vehicle before choosing to install a new engine.

What’s involved in an engine swap with a different type of engine

The project becomes significantly more complex if you aim to replace your engine with a different make, model, or size. This type of engine swap is often referred to as a “custom swap” or “performance swap.” The possibilities here are endless, but the challenges are equally vast.

I’m going to be blunt with you; it’s incredibly expensive to do an engine swap in a modern vehicle using a different engine. It’s not like the old days when all you had to consider was whether the engine would fit in the engine compartment and mate up to the transmission. Those days are gone.

Here’s what you have to consider when doing an engine swap with a different engine

1) Matching ECM and Engine Harness— You’ll need the computer and complete engine harness from the donor vehicle. The different engine won’t run with the existing computer.
2) Matching Transmission and Drivetrain— You’ll also need the matching transmission from the donor vehicle. The new engine’s power and torque outputs must match the drivetrain. This may necessitate upgrading the driveshaft, differential, or axles. If you install a higher-powered engine but use the existing transmission, you risk destroying the existing transmission because it wasn’t designed to handle the higher torque.
3) Matching exhaust— You’ll also need the complete exhaust system and catalytic converter from the donor vehicle.
4) Mounting Modifications— A different-type engine swap typically requires custom motor mounts. In some cases, you may need to modify the firewall, crossmember, or subframe to accommodate the new engine.
5) Matching cooling system—  A different engine may also require a different/larger radiator or transmission cooler.

Choosing an installer to do your engine swap

Choosing the right engine installer is critical to ensuring a successful engine replacement. Not every mechanical shop is equipped to do this kind of job. I’ve done several engine swaps, and I can tell you that if you don’t do this regularly, you can run into problems. In short, a shop that does a lot of engine swaps will know the correct way to drop the engine cradle and separate the engine from the transmission without breaking any components. And they’ll know how to reassemble everything in the proper order to speed up the delivery of your vehicle.

Research and Gather Recommendations:

1. Evaluate the Shop’s Experience and Expertise

Specialization: Choose a shop or mechanic

This image shows the specialized equipment needed to remove an engine from a vehicle

This image shows the specialized equipment needed to remove an engine from a vehicle. A lift table is required to drop the entire engine cradle/subframe from the body.

specializing in engine swaps and major repairs. Performing an engine swap requires specialized lift table equipment to lower the engine cradle and transmission as a single unit (most modern engine/transmission assemblies are removed and replaced from the bottom, not through the hood). Some installers focus exclusively on specific makes and models, which can be advantageous.
Experience: Confirm how many years they have been performing engine installations and whether they’ve worked on vehicles similar to yours.
References: Ask for names and phone numbers of customers you can talk to. Check the shop’s online reviews: Check online platforms like Google Reviews, Yelp, or specialized automotive forums to find reviews about local shops or mechanics.

2. Get a Detailed Estimate

Itemized Costs: The estimate should include a breakdown of parts and labor costs based on an actual inspection of your vehicle. This avoids surprise upcharges for “rust that required additional work.”
Compare Quotes: Obtain quotes from multiple shops to compare prices and ensure you’re not being overcharged.
Transparent Policies: Ensure the shop provides clear policies on additional costs for unforeseen issues during the installation process.

3. Inquire About Warranties and Guarantees

Labor Warranty: Choose an installer that offers a warranty on their work. Common labor warranties range from 6 months to 3 years.
Parts Warranty: If the shop is sourcing the engine and associated parts, confirm whether it honors the engine supplier’s warranty or provides one of its own. You don’t want to be in a position where the rebuilder covers the engine but not the labor cost to replace it if there’s a failure during the warranty period.
Post-Installation Support: Verify whether they offer follow-up inspections or free adjustments if issues arise after the installation.

4. Verify Credentials and Licensing

Bonding, Licensing, and Insurance: A reputable shop will be bonded, licensed, and insured. An engine swap is a huge investment. If something goes wrong, you’ll want to know you have remedies. Fly-by-night shops can leave you with an undrivable vehicle and no recourse.

5. Confirm Turnaround Time

Get a Realistic Timeline: Discuss the expected completion time for the engine installation. Delays can be costly and inconvenient, so look for a shop that can meet your timeline without cutting corners.
Spare Vehicle Availability: Ask if they offer a loaner car or rental discount if the repair takes longer than expected.

6. Evaluate the Communication and Customer Service on the Front End

• Did the shop staff attend to you immediately and schedule an initial inspection?
• Did they willingly answer questions and explain the process clearly?
• Did the shop give you any literature explaining the warranty in detail, giving you time to read the fine print?

7. Verify Insurance and Liability Coverage

Shop Insurance: Confirm that the shop has liability insurance to cover damages or mistakes during the installation process.
Your Insurance: Check with your auto insurance provider to see if any part of the engine installation is covered.

8. Avoid Red Flags

Lowball Pricing: Extremely low estimates might indicate subpar work or hidden fees.
Lack of Reviews: A shop without online presence or customer feedback could be risky.
High-Pressure Sales: Avoid shops that pressure you into unnecessary upgrades or services.
No Written Agreements: Always get written agreements, including warranties, estimates, and timelines.

Is an Engine Swap Worth It?

Ultimately, whether an engine swap is worth the effort depends on your goals. A same-type engine swap is often the most practical solution if you’re reviving a late-model car that’s in otherwise good condition but has a failed engine. On the other hand, if you’re chasing performance or building a unique custom vehicle, a different-type engine swap can be immensely rewarding—provided you’re prepared for the challenges and costs.

Take aways from this article

An engine swap is one of the most transformative modifications you can make to a vehicle. It’s a process that demands a mix of technical know-how, patience, and determination. Having successfully tackled both same-type engine swaps, I can assure you that the satisfaction of turning the key and hearing the engine roar to life makes it worthwhile.

However, I also want to be straightforward about swapping in a different engine to gain performance; it’s far more costly and complicated than most people realize. Unless you’re prepared to spend more than the car is worth, it just doesn’t make sense to upgrade the engine in your present vehicle. You’d most likely come out ahead by buying a more powerful vehicle.

©, 2025 Rick Muscoplat

Posted on by Rick Muscoplat



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