What Does an Oil Filter Do?

Last Updated on March 22, 2023 by Paul S.

The oil filter is the filter that is the least known of the filters in your car. It could be the most important filter in your car because it helps remove tiny particles that can damage the car engine’s mechanical components. 

These tiny particles can be dirt, metals, or debris. Tiny metal shavings can exist in the engine oil because it is part of the natural wear of the internal components of the engine. So as the engine oil is cycled through the engine it will get trapped in the oil filter so that more damage does not occur. 

How Does a Car Oil Filter Work?

The oil filter, which resembles a metal can in shape, functions by screwing it onto the engine. Oil enters the filter through tiny pores on its outside edge and flows through its interior, frequently composed of synthetic fiber filtering mechanisms. This fiber can be made up of different materials.

These materials will help trap particles as small as 15 – 40 microns in size which equates to 0.0005 – 0.001 inches. Yes, that’s small! 

If you are asking yourself how does that cause damage to the engine just think that the engine oil can typically pass through your engine in 15 seconds. During the engine oil’s life of thousands of miles, that can be many passes. If there were sharp objects in the oil then as the oil is flowing through the engine it is causing wear and tear through the components of the engine. Almost similar to what happened to the grand canyon over the centuries. 

After filtering through the oil filter the oil is allowed to protect the engine’s moving parts again and again and again!

When Should You Change Your Oil Filter?

Although every car is unique, several manufacturers’ recommended interval for oil filter change is between every 3,000 to 12,000 miles or more! Like other car parts, the oil filter gets dirty and functions less effectively as it wears down with time. Replace the oil filter every time the car oil is changed. 

Your mechanic will either put a sticker on your car for a reminder or send you notifications to your phone or email. 

How To Change Oil and Filter?

Change Oil Filter
Changing Oil Filter

Changing your oil and oil filter can be more convenient and less expensive than taking your vehicle to your car mechanic or local express lube shop. Oil changes are necessary for the engine to operate at its best. Consult your owner’s manual before you even begin this procedure to find out precisely how much oil you will need to replace what you drain.


  • Latex Gloves 
  • Funnel
  • Jack & Jack stands 
  • Oil Filter Wrench 
  • Oil Pan 
  • Safety Glasses
  • Shop Rags
  • Socket Wrench (drain plug removal)

Drain and change the oil before removing and replacing the oil filter. Follow these 10 steps, and you’ll do the job right in 30 minutes on average:

1. Start the engine 

Run your engine for a few minutes since warm oil drains faster than cold. Parking brakes on. Take out the key. For safety, put chucks behind the wheels. Put on your gloves and safety glasses. 

2. Place the oil pan underneath the oil drain plug after locating it.

If it is not noticeable then you can check with your owner’s manual or check online for the owner’s manual from your vehicle manufacturer. 

Remember that the oil will pour into the pan at an angle. You can use a socket wrench to loosen the plug.

3. Unscrew the plug.

Press the plug back against the pan as you unscrew it to prevent oil from gushing. Watch out oil can be hot! Be ready to adjust your pan as needed to make sure you catch all of the oil. 

Cleaning up oil is not fun and it can be illegal to have any oil drain into the street or into a stormwater drainage system.

Consult your owner manual on where to find the filler cap on top of your engine. By removing it, air may enter from the top, hastening the draining process. 

5. Replace the oil plugs gasket with a new one. This will help ensure that there are no leaks. 

6. Place the oil plug back into the engine

After the old oil has been completely removed, reinstall and hand-tighten the oil plug so it is not cross-threaded. 

7. Locate and remove the existing oil filter. 

The old oil filter may still contain hot oil even after you have drained the oil. Place the oil pan underneath the old filter, and carefully remove the filter with the oil filter wrench. Make sure the gasket from the old filter is not attached to the engine mounting surface by cleaning it with a rag. 

If you do not have an oil filter wrench see the section below on how to remove it without one. 

8. Lubricate the new filter before manually screwing it in. 

Apply oil to the oil filter rubber seal sparingly before installation. Before manually screwing on the filter, check sure the seal is well seated in the filter. 

9. Add the new oil. 

Find the filler cap at the top of the engine and use a clean funnel, and add the amount and kind of oil recommended for your car. You don’t want to overfill it since some oil could not have completely drained out. 

10. Start the engine, then check for leaks. 

Check for leaks in the vicinity of the oil drain plug and the filter after running the engine. Turn the engine off and fix the leak if you notice one. If there are no leaks, turn off the engine and let it sit for a few seconds to allow the oil to drain down in the engine. 

11. Examine the oil level. 

Check your oil dipstick by removing it and cleaning it then placing it back in to measure it. Take it out again to check if it has reached the full mark, and if not, add the remaining oil as directed in the owner’s manual. 

Reminder! Dispose of the used oil and oil filters properly. Bring to an authorized used engine oil drop-off or recycling location. In many locations, it is illegal to dispose of engine oils in the trash. 

How to Remove Oil Filter Without A Special Tool?

All is not lost if you don’t have a specialized wrench for removing your car oil filter. The oil filter removal without a special oil filter wrench is made possible using your hands and something long and strong. There are many other options as well. 

That object is most likely going to be a wrench that is at least the length of the diameter of the engine oil filter. You can simply stab it with the wrench or other piece of metal or wood and then turn it to unscrew it.

The problem with this method is that it will be messy and a lot more difficult than using an engine oil filter. 

Another great way is to use your belt. The belt can be used similarly to how the oil filter wrench is used. Check out this video below on how it’s done!

How Much Does an Oil and Filter Change Cost?

The price of an oil change varies depending on the type of oil your car requires and your area. The average oil change cost is $40-$120 at the mechanic at local and national outlets, versus $25-$60 to DIY for a standard oil change. Thankfully, changing the oil filter won’t break the bank no matter how you do it.

In some cases, you can find deals where the mechanic can do it cheaper. Sometimes the cheap oil change is an incentive to get you in the doors and then make up the difference by recommending other work on your vehicle. 

Just remember that there are a lot of upfront costs to the DIY route that you will need to factor into the total price. So if you only plan to change your oil once it probably isn’t the best option for your wallet. But if you find it fun and want to save a bit of coin here and there it’s a great option. Plus, changing your oil is one of the easiest maintenance items on your vehicle you can do!

Who Makes The Best Oil Filters For Vehicles?

Here are some of the top oil filter manufacturers that are out on the market today.

Oil Filters at the Store

Bosch – Bosch creates some top-of-the-line products for many industries and in the automotive world they are king in terms of price and product. They are one of the more expensive options, maybe it’s because of all that german engineering?

Purolator – As per their website, Puralator patented the first automotive oil filtration system in 1923. So they know a thing or two about oil filters.

Mobil 1 – This oil behemoth makes some of the top oil filters today while also providing gasoline and other products to the world.

AMSOIL – AMSOIL is one of the few independently owned oil companies.

K&N – A mainstay filter company K&N creates top-of-the-line filters because that is their bread and butter. They also specialize in oil filters for your power sports vehicles.

Fram – Fram specializes in filters and oils. They are on the cheaper end of this list but are still utilized in the automotive industry.

Check out our other articles on the other filters in your vehicle. The engine air filter and the cabin air filter.

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