Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. How Do Oil Filters Work?

How Do Oil Filters Work?

oil filter new

At the most basic level, oil filters serve the purpose of preventing contaminants, such as dirt and debris, from reaching the oil in your vehicle. This is important because grit and grime in your oil can damage engine surfaces and components while circulating through the engine’s systems instead of doing its job of lubrication. As a general rule, you should replace the oil filter – a relatively inexpensive part – whenever you have your oil changed as a preventative measure, which varies in frequency depending on the needs of your car or truck’s make and model. This information can be found in your vehicle’s maintenance guidelines in the owner’s manual.

Although the operation of an oil filter sounds fairly straightforward, there are actually quite a few components to this essential part of your engine’s operation system. Here is an overview of the oil filter parts to help you better understand how an oil filter works:

  • Tapping plate/gasket: This is where oil enters and exits the oil filter. It is comprised of a center hole surrounded by smaller holes. Oil enters through the small holes on the outskirts of the tapping plate, also known as a gasket, and exits through the center hole, which is threaded to attach the part to your engine.

  • Anti-drain back valve: This is a flap-like valve that prevents oil from seeping back into the oil filter from the engine when your vehicle is not running.

  • Filter medium: This is the actual filter part of your oil filter – a medium composed of microscopic cellulose fibers and synthetic fibers that act as a sieve to catch contaminants before the oil reaches the engine. This medium is pleated, or folded, for greatest efficacy.

  • Center steel tube: Once the oil is filtered of any grit and debris, it passes back into the engine through a center steel tube.

  • Relief valve: When the engine is cold, such as upon start-up, it still requires oil. At low temperatures, however, the oil is too thick to pass through the filter medium. The relief valve allows small amounts of unfiltered oil into the engine to meet lubrication needs until the oil has heated enough to pass through the oil filter normally.

  • End discs: On either side of the filter medium lies an end disc, usually made of fiber or metal. These discs prevent unfiltered oil from reaching the center steel tube and passing into the engine. They are held firmly in place against the tapping plate by thin pieces of metal called retainers.

As you can see from this list of oil filter parts, answering the question of how a filter works involves more than just sifting out debris through a filter medium. Your vehicle’s oil filter is designed not just to remove contaminants but also to keep the filtered and unfiltered oil in their proper areas as well as feed oil in a less-than-desirable form when the engine requires it. If you have any confusion regarding how an oil filter works or suspect there is an issue with the filter in your vehicle, don’t hesitate to call one of our knowledgeable technicians for a consultation.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Shutterstock.com Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....


Related questions

Q: Smell coming from A/C vents

It sounds like you have a leaking heater core inside the evaporator housing and would need to have it replaced. If you have the heater bypassed then you will not have heat inside the car and the temperature control will...

Q: Advice on using oil combinations and changing oil

Yes, I would use a higher-quality filter because if you do use a higher-quality filter with that synthetic oil, you can change your oil every 7,000 or 10,000 miles instead every 5,000 miles or 3,000 miles. I would use a...

Q: How much oil does the engine hold?

Knowing the amount of oil your engine holds is important even if you don’t do your own oil changes. If you drive a 4-cylinder Accord, your engine holds 4.2 quarts of oil (including the filter). If you drive a V6...