There are several reasons why you may want to swap your Audi A5 engine. For many people, it’s one of the most interesting ways to get improved performance out of your A5. For others, it can be a fun and rewarding project to undertake during your free time.
With so many engine options out there, the biggest question is always what motor to go for. Audi vehicles are powered by motors that come in all shapes and sizes. Not all of them will fit in your A5, unless of course you’re doing a direct like-for-like replacement.
In this guide, we are providing an updated Audi A5 engine compatibility chart that will guide you on the engines to go for. We’ll also dive deeper into what you need to know before doing an engine swap and the challenges you’re likely to face.
The first step before doing a motor swap is usually to pick the right type of engine. This will determine the level of success you’ll have and the cost of the A5 entire project. It will also dictate how much time you’ll put into it, and that’s why an engine swap compatibility chart is important.
But, before going through the chart provided below, find out the year and trim level of your Audi A5 if you already haven’t. This will help you to know what type of engine is fitted in your car. The chart provides a list of engines by model years alongside other vehicles that have the same engine under the hood.
If you’re not sure what type of engine is fitted in your Audi A5, the next section of this article will help you determine this as well as know the specifications of the motor. Once you’ve obtained the information you need, come back to the chart for a compatibility check.
The quickest way to determine the type of engine your vehicle has is to search the engine database on our website. This works well if you already know the specifics of A5 you drive, like the year of manufacture, and trim level.
If you do not have any of this information, you’ll need to locate the VIN. This is a 17-character identification number that provides details about your car. You can find it on the side of the driver’s door frame, dashboard, in the trunk under the spare tire, on the rear wheel well, on a metal plate under the hood, or somewhere near the engine.
Using it, you can tell where your Audi A5 was built, who built it, its type or division, brand, body style, and so much more. The eighth digit contains information about the engine, including the number and arrangement of cylinders, the fuel used, and the fuel injection method.
All you need to do is write the VIN down and search for a VIN decoder online. Type the number as copied and press ‘Search’ or ‘Decode.’ You may have to select the trim level of your vehicle before accessing the information. Scroll through the results to see your A5’s engine type and specifications.
Swapping your A5’s engine with another isn’t easy. This is especially true if you cannot tell whether the new engine will fit in your car. It requires a lot of research, both online and on the ground. Scrolling through various guides and forums on the internet should tell you whether an engine will fit or not.
However, if you’re still not sure, you’ll have to do it the old school way. Start by finding the engine and measuring its general dimensions. Check where the oil plan goes and whether other parts of your Audi A5 may get in between the swap.
Batteries and wiring harnesses can be moved around. However, if the shock towers and firewall are in the way, it may be wise to pick another engine. Below are more compatibility issues you need to keep in mind.
Axles and Drivetrain Considerations
The new A5 engine needs to send power to the wheels. Otherwise, it will be no good. The first thing is to determine whether you have a front-wheel-drive (FWD) or a rear-wheel-drive (RWD).
The former uses an axle to transmit power to the wheels while the latter uses a driveshaft. You’ll need to obtain a custom axle or custom driveshaft as the existing one may not be able to handle the additional power of a bigger engine.
Measure the distances where they fit and ensure that they have the corresponding joints that fit on either sides.
Pedal Assembly Communication with the New Engine
The pedal assembly of Audi A5 needs to communicate well with the new engine. The last thing you want is your gas pedal bailing on you in the middle of the highway. Older Audi vehicles typically use cables to control the throttle body every time you step on the gas.
These can be easier to swap as you’ll only need a new cable that works with the engine. In newer cars, however, things can get complicated. The electronically controlled throttle system needs to work effortlessly. This is done by ensuring the ECU, pedals and wiring are in sync.
The same goes for the clutch. Older cable-operated clutch systems tend to be easier than hydraulically operated systems. The latter may require additional parts, such as a high-pressure adapter line.
It’s never a good idea to change A5’s shifter components during an engine swap. This can make the process messy and a lot more time-consuming. It’s best to just go with the new transmission components without trying to mix things. You may need to modify the shifter tunnel just a bit to allow things to fit, but anything beyond that may not be necessary.
Possible Fuel System Issues
A new engine usually comes with its own fuel rail. The first step is to ensure the rail connects well to the fuel line, fuel pump, fuel filter, and other lines. The filter and pump can always be reused. However, you may need a stronger fuel injection hose that can handle the increased pressure. This is not a hard process, but any mistakes can quickly turn your vehicle into a ticking time bomb.
Cooling System Modifications
Both air and coolant need to flow into the engine unobstructed to prevent it from overheating. The coolant also needs to flow back into the radiator. For bigger engines, any modifications made to the cooling fan should be taken seriously.
The fan should be positioned correctly to allow air to pass through the A5’s radiator and get pushed or pulled in the right direction. You may also need to source better heater and radiator hoses from the engine manufacturer.
A/C and Power Steering Compatibility
You’ll most likely not be able to cheat your way through the A/C and power steering if they are incompatible with the new engine. This happens quite often if most of the parts are mechanical. The steering pump and A/C compressor may fail to fit back into the car when doing the swap.
However, the two can always be modified. You’ll need to first study the engine and car parts to figure out how they can be combined. Some welding may be required to fit high-pressure lines. You may also need to source for aftermarket brackets to hold the A/C compressor.
Customizing Intake and Exhaust
The intake and exhaust of your Audi A5 will most likely be custom-made, unless you’re fitting a like-for-like engine. The model and type of engine will determine what you’ll use. For the piping to fit, you may need to reroute, shorten, and do some welding for compatibility. Additional piping may be necessary to ensure the exhaust manifold fits into the existing exhaust system.
The new engine needs to communicate with the A5’s electricals and send the right signals to the dash. This boils down to whether the ECU works with the engine and if the wiring has been done correctly.
When using a completely different engine model from different manufacturer, a new management system will be necessary. The wiring for the chassis, dashboard, and engine will need to be just right. Otherwise, it could turn your vehicle into an unusable piece of metal.
Upgrading Suspension and Brakes
A larger and more powerful engine is likely to add weight and strain to your existing suspension and brakes. This is especially if the Audi A5 was originally designed to handle a smaller and lightweight engine.
A high-performance coilover system and dampers will be a necessity to help reduce shock on the road. Better and stiffer braking components should also help to maintain or improve the vehicle’s braking abilities.
Things That Get in the Way
Other considerations may include having to install a taller hood to help with clearance. You may also come across more components inside your Audi A5 that need modifications, relocation, or complete replacement to make things work.
Let’s not also forget about the legal implications of all the work done. Depending on the state you live, you may need to spend more money on equipment and sensors to keep emissions low and your vehicle compliant with the law.
Increased engine power
The main reason why most people perform Audi A5 engine swaps is to get more engine power, performance and efficiency. A bigger engine can turn a small car into an enthusiast’s fastest vehicle. This is especially if it’s fitted with a high quality fuel system and high-performance parts.
Revives a dead car
Those of us that into classic cars would find it refreshing to see a dead A5 from back in the day hit the streets again. Engine swaps can help equip older stylish Audi vehicles with a more modern engine that brings them back to life and makes them comfortable to drive.
Building A5 Project
A lot of mechanics and car enthusiasts find engine swapping fun. It’s a difficult challenge that can be rewarding to solve. It’s especially fun for those that like to fix and bring back cars to their functional form.
It will take somewhere between 5-10 working hours to swap an engine with another one that bolts right in. You can expect the work to extend between 2-3 days if you’re taking it to a mechanic or professional.
Working with a different engine whose process and documentation is well supported will take you anywhere between 40 and 80 hours. Depending on your experience, time available, and creativity, an engine swap done on completely new ground could even take more than 10 years (no kidding!).
Swapping an engine is a hard process that needs extra care and attention. There’s usually a lot that can go wrong, even when using a complete kit with instructions. Audi engines are built differently and require their own electrical wiring, fuel delivery, transmission, steering, and modifications. If you’re really good at what you do, you can expect to complete it in a few days or weeks.
The cost of swapping your engine for another can range from $0 to more than $20,000. You may have an engine lying around or need to get a new one before getting started. However, it all depends on the type of engine you choose for your A5, whether you’re doing it yourself or taking it to a professional and the cost of tools and extra parts you need.
The general process on how to install an engine on Audi A5 correctly will typically look the same but with variations based on the engine type and nature of the project. The following are some of the steps you’ll need to take.
As a precaution, never install salvaged or damaged parts with your new engine. Always ensure that you check the Audi’s instructions before undertaking the work. This will help avoid any unnecessary mistakes and guide you through the entire process.
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