Skip the auto shop - Our mechanics make house calls

How Does Oil Lubricate an Engine?


You're on your way to work and the the Check Oil Light comes on. You may not know how the oil lubricates and protects the engine, but you know it's an important part of keeping your car running. You take the time to make an appointment with YourMechanic to ensure the oil is doing its job and there are no leaks. It's a good idea to understand what the oil does and where it goes under your hood, so you can understand why it's important not to ignore a low oil or check oil light. Here’s a bit about how oil works to lubricate the engine.

Starting the journey

The journey begins in the oil pan which is like a train station where the train stops off when the car isn’t running. The oil pan is also known as the sump and holds between 4 and 6 quarts of oil, depending on the size of the pan. As soon as the engine roars to life, oil leaves the oil pan through the oil pump where it’s strained to remove any contaminants. It next travels through the filter to get the smaller particles. This helps ensure these particles don’t get transferred to the engine where they can cause problems.

Moving on down

The oil continues its journey into the spaces and channels of the engine. It goes in between the bearings and through the crankshaft. The rod bearings and main bearings have small spaces between them and the other components, which must be lubricated to prevent contact.

The majority of the oil stays in the crankshaft area, but a small amount goes to the camshaft or the valve lifters, and the rocker arms. Gravity pulls the oil down to the head and the motor block. It ends up back in the oil pan where it starts a new round.

This process is the same on all vehicles, except for one big difference. Most cars use a wet sump, but a few have a dry sump. A wet sump is where the oil pan lies at the bottom of the engine, while the dry pump is elsewhere. In fact, it can be placed in many places around the engine, but isn’t on the bottom. There’s more flexibility to the design of the pan when it can be located elsewhere. It also doesn’t overdose the crankshaft on oil, which improves horsepower.

If the oil runs low, it won't be able to move through the components and provide lubrication to all of the moving parts. These parts can become worn and damaged as they hit against each other. Make it a priority to check your oil level and have a mechanic look at your car if you think it's leaking oil.

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

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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.


Post a question and get free advice from our certified mechanics.


More related articles

Symptoms of a Bad or Failing Starter
Common signs include the engine not turning over, starter engaging but not spinning the motor, and grinding noises or smoke when starting the motor.
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
Symptoms of a Bad or Failing Flexible Clutch Hose
Common signs include difficulty shifting, low clutch fluid, and feeling no resistance at the clutch pedal.

Related questions

Q: Exhaust pipe oil leak

The oil pan may appear wet, but the leak may be running down from a higher place on the engine. The valve cover gaskets or camshaft seals may also be leaking down. Washing down the engine and adding U/V dye...

Q: What type of oil and oil filter should I use for my Jeep?

With 203k miles, I would recommend a 'High Mileage' oil and a standard oil filter. With a 5.2 liter engine, that mileage, and after sitting for some time, I would recommend a 5w-30 oil change, running it for 500...

Q: Fuel in oil possible causes

There is only a couple of ways fuel can get into the oil. One possibility is that the fuel injection pressure regulator has a leaking valve and it leaking fuel into the vacuum line. Another possible cause is that one...