Oil Catch Can: What It Does, Advantages, Disadvantages, and FAQs

An oil catch can keeps the engine’s intake manifold clean, improving its performance and efficiency. It’s a crucial part of any direct injection engine, which is why knowing how this engine type works is the first step to understanding how it works.

What Is Direct Injection Technology?

Direct injection technology is a system in modern-day vehicles with diesel and gas engines.

It directly injects the fuel into the main combustion chamber of each cylinder before mixing the air and fuel inside the chamber. On earlier gasoline systems, the fuel injectors sprayed gasoline mist directly on the intake valve, which tends to keep it pretty clean.

The problem with some early gasoline direct injection platforms is that the valves tend to gather sludge from the oil steam drawn into the intake by the PCV system and this can lead to thick, dense sludge deposits on the intake valves that reduce volumetric efficiency. That being said, many newer gasoline direct injection platforms now have an extra set of MFI injectors above the intake valves that work with the direct injectors to supply fuel, mitigating the valve deposits.

Direct Injection: What Does an Oil Catch Can Do?

The oil catch can separates the oil droplets from the air that flows from the engine breather and the intake system.

Pressure from the combustion chamber can get into the crankcase or the oil pan. Oil droplets form when the pressurized air comes in contact with moving engine parts.

The vaporized oil then escapes through the positive crankcase ventilation (PCV) valves. It gets processed in the combustion chamber and, by extension, the different emission control devices downstream of the combustion chamber to ensure it doesn’t contribute to air pollution.

The oil catch can connects to the PCV hose so that the pressurized air travels from the bottom of the catch can, through a tube, back to the top of the can, and towards the outlet passing through a filter. The oil naturally condenses and settles into the bottom of the can, reducing the oil steam that is being drawn into the intake while still allowing the PCV system to do its work.

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Pro Tip: On some older Cummins engines in Dodge pickups without PCV systems, an oil catch can was literally a can tied under the crankcase vent to keep oil from dripping on the driveway. But there is also what might be called a PCV filter that allows the PCV system to operate normally yet prevents most of the oil steam out of the intake manifold.

Advantages of Using an Oil Catch Can

Oil catch cans improve engine performance by protecting the intake manifold and valves from contamination (oil particles).

Disadvantages of Using an Oil Catch Can

Getting an oil catch can revokes the validity of the engine’s warranty because installing the oil catch can is considered a modification to the PCV system. In states where emission systems are regularly tested and inspected, this could bring heavy fines if the catch can is revealed. Research your own state’s regulations before installing an oil catch can.

The change also disqualifies the vehicle for smog detection, but the car owner can always remove and reinstall the device when performing a smog test.

How to Install an Oil Catch Can

Oil catch can installation usually involves the following steps.

• Step 1: Remove the engine cover and pipe.
• Step 2: Find the catch can’s intended location and secure the bracket.
• Step 3: Install the fittings onto the catch can and use a thread sealant to prevent leaks.
• Step 4: Attach pre-formed hoses to the crankcase and intake system. Modify the hoses if needed for a snug fit.
• Step 5: Use a check valve to prevent the backflow of contaminants and make sure the hose isn’t bent.
• Step 6: Connect the hoses to the catch can inlet and outlet before securing them with clamps to prevent displacement.

If you’re not confident with your auto repair know-how, it’s best to leave the installation to a licensed mechanic.

FAQs About Oil Catch Cans

Here are the answers to some of the frequently asked questions about oil catch cans.

Will an Oil Catch Can Improve Performance?

Yes, it can improve engine performance, as it prevents oil from entering the combustion chamber. This limit knocks and pinging when you accelerate because the air/fuel mixture won’t detonate in the cylinders.

Do Oil Catch Cans Improve Fuel Economy?

Oil catch cans don’t directly improve fuel economy, but they do help by limiting engine wear and tear caused by knocking and pinging.

Do Oil Catch Cans Increase Horsepower?

Oil catch cans slightly increase horsepower by decreasing the amount of unwanted oil that enters the engine, reducing the risk of pre-ignition and knocks. This results in a more controlled air and fuel mixture in the cylinders, which improves combustion efficiency.

How Can You Tell if the Oil Catch Can Is Full?

The oil catch can might be full (and in need of a replacement) when there’s liquid at the bottom and when the engine runs rough.

What Happens When the Oil Catch Can Is Full?

A filled oil catch can could reduce fuel efficiency, lower driving performance, or even damage the engine when the oil vapors aren’t properly emitted.

How Often Do You Need to Change the Oil Catch Can Filter?

Replace the oil catch can filter once every 500 miles to ensure it’s not overfilling and causing a mess in the engine area. You could also replace it every time you replace your oil to save time.

Final Thoughts

Installing an oil catch can is beneficial to your engine because it filters out debris and other impurities. This keeps the intake manifold clean, resulting in improved performance and better efficiency. Replace it every 500 miles or each time you change your oil to keep the engine clean.

Where to Get an Oil Catch Can for Your Vehicle

Oil catch cans come with a lot of advantages, and you can take advantage of them when you shop for one at CarParts.com.

Simply use your mobile device or computer to visit our website. Our catalog includes accurate and detailed fitment information, so you’re sure to get exactly what your car needs.

We source our components from the most trusted manufacturers in the industry. Each item in our catalog is carefully vetted by a team of experts to guarantee both quality and durability. You won’t have to worry about your new oil catch can failing you any time soon.

On top of that, our warehouses are strategically located across the US, meaning you can receive your order within days. Every item in our catalog is also available at competitive prices, so you won’t have to break the bank to get your hands on what you want.

Improve your vehicle’s performance now. Order an oil catch can that’s built to last with CarParts.com.