Oil In Catch Can – An In-depth Analysis

The oil catch can is an important device that helps to protect your car’s engine intake from oil and other contaminants buildup. The component is usually installed between the intake manifold and the positive crankcase ventilation (PCV) valve.

The device helps to separate microscopic oil droplets away from the crankcase air so that the air can resent to the engine. After that, the oil is channeled into a reservoir or sent back into the car’s engine sump.

However, the oil in catch can must be treated with care to avoid unexpected damage. If you’re contemplating how to remove oil from a catch can carefully read this article.

How To Install An Oil Catch Can
Image Credit: POWERNATION YouTube

What Causes Excessive Oil In Catch Can?

Driving for too long without checking to empty your vehicle’s oil catch can will eventually cause a lot of oil to be trapped in the component. This can result in a costly problem in your car.

Therefore, expert auto technicians recommend that you empty your oil catch can when necessary, depending on your driving style, how far you go, weather conditions, and the driving conditions. These factors that make the catch can fill up fast.

So, you may want to attempt driving 500 miles when you first install a new oil catch can and empty the container. Meanwhile, ensure to empty the liquid into a bottle in order to measure the quantity.

You will be able to ascertain how fast the catch can fill up so that you can empty the fluid within that time frame. However, it is important to note that you will most likely have more fluid in the catch can during winter because of the condensation that will form in the component.

How Do You Remove Oil From A Catch Can?

Again, failure to empty your oil catch can may eventually harm your vehicle. However, knowing how to remove the oil from the component is essential. The following is a step-by-step process of emptying your oil catch can.

Take off the catch can from its position.

Firstly, carefully remove the oil catch can from its position and slide it through to the edge of your engine bay for easy draining.

Put it in a horizontal position

Since you will be draining the fluid from the bottom, ensure to place the component in a horizontal position before moving to the next step.

Remove the scroll at the bottom

Now, remove the screw at the bottom of the catch can (depending on the type of catch can you have) to allow the fluid to drain out.

Place a bowl underneath the catch can

Ensure to place a bowl or small container under the catch can to collect the oil drain as you turn it to remove the oil from the component.

Fix the screw and reinstall the catch can

Once you finally drain out the oil, fix the screw back on the bottom of the catch can and tighten it up with a wrench. Then, reinstall the catch can back to its original position. Now you are good to go. You may want to check out this video for visual guidance.

Should A Catch Can Have Oil In It?

The main purpose of a catch can is to trap excessive oil from entering the intake manifold in order to protect the component from oil and other contaminant buildups. Therefore, the catch can will eventually have oil in it over time.

However, the oil must not be allowed to accumulate for too long to prevent unexpected damage caused by too much oil in a catch can. That’s why the manufacturers and professional auto technicians advise that you empty the fluid in the catch can after a while, depending on how far you drive. Ideally, you should check the content after 500 miles.


Q: Why not to use an oil catch can?

Installing an oil catch can automatically modify the positive crankcase ventilation (PCV), which is illegal since the component is part of a vehicle’s emission system. In other words, using an oil catch can be simply going against emissions regulations.

If you were wondering, “Why are oil catch cans illegal?” The simple answer is because of their interference with the emissions system in a car. Besides the illegal aspect of tampering with the emissions system, installing an oil catch can may be quite expensive, depending on the model you choose to buy.

Q: How often to empty oil catch can?

The time frame within which you should empty your car’s oil catch can depend on how hard you drive. However, you may want to empty the component every time you perform an oil change. However, some car owners empty their oil catch can after every 500 miles.

However, ensure to observe how often the catch can fills up in your car and do the needful. You may want to consult a professional auto mechanic for proper guidance.

Q: Can a catch can cause problems?

Yes, an oil catch can will most likely result in poor oil filtering. This is a major generic issue with the various brands of catch cans in the automotive market. Also, the component prevents a car from detecting smog, which is against environmental law.

The worst-case scenario of using an oil catch can is engine failure. Unfortunately, if a car’s engine breaks down due to using a catch can, it may not be covered by a warranty.

Q: What is the disadvantage of oil catch can?

One of the major disadvantages of an oil catch can is that the component alters the guarantee on a vehicle’s engine. It can also make a technician fail you when performing an emissions test on your vehicle.

Therefore, inasmuch as the component has some benefits, it is also important to consider the disadvantages before opting for one. Fortunately, most modern vehicles do not need an oil catch can as they are fitted with systems that serve as an alternative.

Q: How much oil does a catch can catch?

An oil catch can hold around 150ml of oil. Unfortunately, most of the component does not feature a dipstick which helps to ascertain the level of the content. Therefore, it would be best to check it often in order to avoid having a lot of oil in a catch can.

However, the extent of your vehicle usage determines how fast the device fills up, requiring you to empty the oil.

Q: What does oil in a catch can look like?

Oil in a catch can look like coffee with a mix of creamer. This is similar to the look of chocolate milk. It’s normal to have the oil in the component this way. However, it is crucial to ensure that you don’t accumulate excessive oil in a catch can.

Therefore, ensure to find out the recommended intervals to always empty the content of your vehicle’s catch can in order to avoid any form of the engine problem.

Q: Why is there sludge in my catch can?

Having sludge in your vehicle’s oil catch can indicate that there’s water in the oil. Usually, this occurs during cold weather. Under such weather conditions, the oil will be mixed with condensation in the catch can, resulting in sludge.

Maintaining the oil catch can is very important. Manufacturers advise that you empty the container to get rid of water in an oil catch can. You may want to ascertain how fast your catch can fill up to know when to always empty the content.

Q: Is an oil catch can good for your engine?

Oil catch can play a vital role in enhancing a vehicle’s engine performance by helping to retain residual oil and protecting the valve and intake manifold from pollution. However, besides the oil catch can benefits, the component comes with a couple of drawbacks.

Using an oil catch can kit may not be permissible in some countries because the component will most likely alter the emissions system in a vehicle.

Q: Do catch cans reduce oil consumption?

Of course, oil catch cans help to minimize oil consumption in most vehicle engines. However, this may not be the same in some engines. The component just works on trapping excess oil that could build up in the intake manifold.

Generally, the oil catch can improve a vehicle’s engine performance and extends its lifespan. However, you must take note of the expected interval to always empty the oil in the catch can.

Final Words

Undoubtedly, the catch can play a vital role in protecting your car’s intake manifold. However, installing the component is not enough. It is important to consider the oil catch can pros and cons before buying the aftermarket part.

Meanwhile, excess oil in catch can is a major challenge to be aware of when installing the device. However, it is pretty easy to avoid if you can ascertain how fast the component fills up.

Besides, the problem resulting from too much oil in the catch can, the component may be illegal in some locations due to the alteration the device causes to a vehicle’s emissions system.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

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