Causes of Oil Filter O Ring Leak and Fixing Process

The oil filter O ring is a seal that helps prevent oil leaks and contaminants from getting into the filter. When the seal is damaged, you will experience an oil filter o ring leak. It could happen for many reasons, such as during the installation process, wrong seal size, etc. The important thing is that you notice the leak fast enough before it can get to other parts of the engine, like the spark plug, and immediately replace the seal.

oil filter o ring leak

What Is The O-Ring On An Oil Filter?

The O-ring is the oil filter seal; it prevents the filter from leaking oil. Every oil filter comes with an O ring that you can find at the top of the filter. It completely seals the filter from contaminants, such as dirt, water, and more. It does not allow oil to escape from the filter when driving.

Like other vehicle parts, you could experience a leaking oil filter through o ring. When this happens, it could result from a faulty O-ring. The O-ring could have shifted out of place or become damaged entirely. After some use, the O-ring can experience wear and break, leaving space for the oil to leak into other engine parts. Remove the defective oil filter to avoid further engine damage.

Causes of Oil Filter O Ring Leak

Some factors could cause the O-ring to leak, and some of them may include the following.

1. Heat

One of the common causes of oil filter o-ring leak is heat. The seal is made up of rubber components, and when exposed to a lot of heat, it gets hardened. When this happens, the ring loses its elasticity and can easily break.

There is a maximum amount of heat the ring can handle before it becomes hardened. Also, when there is excessive temperature cycling, the ring will get hardened. As it hardens, oxidation begins to take place, which then causes the ring to crack and break.

2. Installation damage

 You can cause a leak in the o ring oil filter during installation. When installing the oil filter and placing the O-ring, you must ensure that there is no cut in it. It is easy to get cuts on the ring due to the sharp edges present when installing the filter.

Also, a significant factor that could cause the O ring to get damaged during installation is a ring that is different from the exact size for the filter. In figuring out how to get the ring to fit, you could cut it.

3. Swelling

A swelling O ring is a common thing that could result from two things. They include incompatibility with the environment and chemically induced swelling. Some O-rings will swell when the ring reacts to the conditions of the environment.

Chemically induced swelling could happen when the seal absorbs liquids or other foreign substances, which would react with its chemical components causing it to swell uncontrollably.

How Often Do O-Rings Need To Be Replaced?

The o-ring can last up to 10 years but should be changed any time you change the oil filter. When changing the oil filter, the o-ring could be damaged or unsuitable for the new filter. It is why every oil filter comes with at least two o rings, so you do not have to buy one.

An oil filter can be used for up to 7,500 miles, depending on your vehicle type and oil. If you use conventional oil, the oil change may be sooner than that, so you will also have to change the filter. It means that you should change the o-ring around that time.

Oil Filter O rings You Tube

However, if you notice oil leaking from the oil filter, you should check out the O- ring and get it changed immediately if damaged. You should not always wait until the expected period to change the filter before checking it and replacing it if damaged.

Other Causes of Leaking Oil Filter

Apart from the o ring seal, other factors could cause a leaking oil filter, including the following.

1. Damaged cap

A damaged cap could cause the oil filter to leak oil. The cap is meant to be airtight, not letting anything get into the oil or let oil out. When the cap is broken or worn out, it will not be able to perform this function properly. It will create a gap for oil to escape and allow other elements to get into the oil, causing contamination.

2. Damaged Filter housing

Many vehicles have filter housing that does not allow them to apply the oil directly into the engine. Oil leaking from oil filter housing is a common thing that could happen, as the housing could get damaged suddenly from exposure to excessive heat and over tightening housing. Check the house cap and thread for damages and also examine for heat damage.

3. Over or under-tightening

You must tighten the cap just the right way. Under tightening the cap will give space for oil dripping from the oil filter and no oil in filter may be occurred. When the cap is over-tightened, it will damage, cause damages, the thread will become worn out or broken, or you could damage the cap itself.

4. Wrong size of the filter

When you do not have the right size of filter installed, you will have a loose oil filter. With an undersized filter, the oil will be able to escape freely. There will be a lot of space available, which will not allow proper sealing from the o ring.

5. Double gasket

The double gasket oil filter will lead to an oil leak. A double gasket is when a new filter is installed on an old seal. It could lead to a complete blowout of oil as soon as you start the engine. Sometimes the blowout could be stalled and could happen after a few minutes of driving.  

How to Fix Oil Filter Leaking

The Oil filter leak fix you will adopt on the cause of the leak. As we know, there are different causes of the leak. You should first check for the cause of the oil filter leak and then fix it.

If a defective oil filter causes the leak, you may need to change the filter immediately. When changing the oil filter, change the oil ring or seal to avoid oil blowout when driving.

Also, try and examine the cap for damages; any damage to the cap could cause an oil leak. Once you find damage on the cap, you need to have it changed as soon as possible.

In addition, you could experience an oil filter housing leaking after an oil change; when this happens, you need to replace the housing. First, examine the housing for any damage because the leaking could be from another source.


The o ring is an essential aspect of the oil filter. It needs to be checked regularly, and a majority of the leaks from the filter can be traced to it. When installing the oil filter, you must be careful with it, especially around sharp edges, and ensure it does not get cut. Also, ensure the o ring is the right for the filter. Otherwise, you may face oil filter o ring leak. Finding the right size is not usually the problem, as most oil filters come with an o ring. However, if you try to fix the seal and it is a lot more complicated, it might not be the right size for the filter.

Akindayini Temiloluwa

I am Akindayini Temiloluwa, an automotive expert writer and car enthusiast. I have over three years of experience in the automotive writing niche and have completed over 300 pieces of content from 50 projects. I have vast knowledge and skill in vehicle repairing, all mechanical work, car upgrades and maintenance. My goal as an automotive content writer is to simplify the most challenging concepts for my readers, help them self-diagnose what may be wrong with their vehicles and offer real value for their time.

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