The benefits of air oil separators

Tuesday 31st January 2023

For vehicles, air oil separators (AOS) provide a critical function in separating oil vapours from your air intake. If oil vapours pass through into the air intake of a vehicle, this can lead to oil loss, and also, it can cause problems for the performance of your vehicle. 

Unlike a catch can, an air oil separator has more functions than simply catching the oil, which means regular emptying and drainage are required. Want to know more about the benefits an air oil separator provides? Read our blog below to find out more.

What are the basic functions of an air oil separator?

It is a common misconception that catch cans and air oil separators perform the same functions- to catch oil vapours before they reach the air intake track of a vehicle. 

This is important as if the oil vapours pass through into the air intake, this can create carbon deposits or damage the octane of your fuel, causing tuning and performance issues for a vehicle. Where catch cans and air oil separators differ is in how they filter the oil once it is captured. 

Catch cans simply capture the oil, and require frequent drainage, whereas an AOS performs more elaborate filtration techniques.

How air oil separators work

Generally, an air oil separator will have a thin hose attached to it. The air passes through a very fine filter and is directed towards the separator. 

The oil cannot pass through, and thus it becomes separated from the air. The oil is collected within the separator and is redistributed into the engine’s oil supply. An AOS can differ in its functionality, depending on the product. 

Some contain additional baffles and chambers within the vessel to perform more filtration of oil from air.

Why are they needed?

There are lots of advantages an AOS provides a vehicle, particularly those that are prone to oil build-up. Benefits for vehicles include the following:

Improved performance

As the oil is filtered, the engine is protected, and therefore runs smoother. The oil is also recycled for better efficiency.

Preventing unnecessary oil loss

If a vehicle is losing oil that could be recycled, then the efficiency of the vehicle is not being maximised, and the running costs will increase as a result. Air oil separators ensure that oil is repurposed effectively.

Minimising oil-build up

One of the primary functions of the separator is to avoid the recirculation of oil into the cylinders, which clogs airflow and slows performance. 

The build-up of oil affects the overall performance of the vehicle, and if the cylinder becomes blocked, this can lead to potential combustion. An air oil separator negates this and improves the overall functionality of the vehicle.

Useful for cars with a direct injection engine

Many vehicles now come with a direct injection engine, as they are better for performance and fuel economy. 

Rather than using a manifold fuel system, direct injection engines use internal combustion, which can lead to issues with excess oil vapours and residue. Therefore, an AOS can be a useful tool to deal with this side effect.

How to install an AOS

Installation is fairly straightforward, but the vehicle will need to have a positive crankcase ventilation (PCV) system to enable this. 

Each AOS will have guidelines for installation that may differ slightly, but generally, the way to approach the installation process is set out below. 

Ensure you have an appropriate pair of cutters for the hoses and a good-quality sealant to apply around the AOS. Locate the PCV hoses and mount the bracket for the AOS in an appropriate location near to the PCV lines. 

Disconnect the hoses and remove any existing catch cans should there be any. Connect your AOS to the PCV lines and connect the drain hoses to the oil system. Mount the hoses onto the bracket and then reconnect the PCV hoses.

The best air oil separators at Filtration Ltd

If you’re looking for industry-leading products, then Filtration Ltd is the place to locate the best air oil separators on the market today. We have a wide range available online for all your needs, so why not take a look at our offerings. 

We also stock thousands of different lines, including air, coolant, and HVAC filters, amongst many more. If you require expert guidance or advice on anything filtration related, then contact us, and we’ll be more than happy to assist you.

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