How Does Oil Lubricate an Engine?

Surely you know that oil is important for your engine, but perhaps you don’t know why. After fuel, engine oil is the most essential fluid in your vehicle, and without it you wouldn’t get far. The main purpose of oil is to lubricate and cool the components in your engine. Between combustion and friction, engines generate a lot of heat, and oil helps to keep things moving and prevent overheating. Given how vital oil is, it’s important to understand how it works, and why you should never ignore an oil leak or Check Oil Light.

Starting up

Engines generally hold between four and eight quarts of oil depending on their size and type. When your car is turned off, oil collects in the oil pan (also known as the sump), usually situated at the bottom of the engine. As soon as the engine roars to life, the oil pump begins to work, first moving the oil through the oil filter, which strains the oil to remove contaminants and particles which can damage engine components.

After the oil filter, the oil flows through galleries running throughout the engine. Galleries are the tubes, channels, and pipelines that ensure oil is delivered to all necessary components. The crankshaft and bearings are doused in oil and have galleries running through them, keeping them cool as they spin rapidly. Spurt holes spray oil on the undersides of the pistons, helping control combustion temperatures and reducing friction as they move up and down in the cylinders. Oil also lubricates the camshaft, valves, and valve springs to keep them moving freely.

Gravity and the continuous flow generated by the oil pump keeps oil moving throughout the engine. After oil has circulated through the engine, it’s sucked through other galleries back into the oil pan, where it again passes through the oil filter and starts the cycle anew.

Wet vs. dry sumps

Most cars use a wet sump, but some have a dry sump. A wet sump is where the oil pan sits at the bottom of the engine, and a single oil pump works to move oil through the galleries. A dry sump has an oil reservoir located elsewhere (specifically not at the bottom of the engine), and uses at least two oil pumps to keep oil circulating. There’s more flexibility to the design of the pan when it is located elsewhere; however this system is more complex and expensive to design and build. Dry sump systems are often found in performance cars, as they offer certain benefits for engines that frequently run near the redline or under high cornering loads.

There’s a risk of damage if your engine is leaking or burning oil. A low oil level condition means there might not be enough oil to sufficiently lubricate all the parts, making them wear out faster and overheat from friction. Old, dirty oil also won’t flow as well through the galleries and can leave sludge on parts, so it’s important to get an oil change every 3,000 to 7,000 miles. A certified mobile technician from YourMechanic can change your oil at your location using high-quality Mobil 1 oil.


Next Step

Schedule Oil Change

The most popular service booked by readers of this article is Oil Change. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. We currently cover over 2,000 cities and have 100k+ 5-star reviews... LEARN MORE

SEE PRICING & SCHEDULING

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

Recent Oil Change reviews

Excellent Rating

(28,142)

Rating Summary
26,601
957
209
107
268
26,601
957
209
107
268

Pardeep

22 years of experience
1277 reviews
Pardeep
22 years of experience
Scion xB L4-2.4L - Oil Change - San Jose, California
Pardeep was very professional. Finished all works in a timely manner. Will again avail of his services when the need arises. Highly recommended.
Ford Fusion - Oil Change - San Jose, California
Great experience. Of all the online services, this one makes sense. I got the oil I wanted and great service

Simon

28 years of experience
378 reviews
Simon
28 years of experience
Mercedes-Benz 190E L4-2.3L - Oil Change - Washington, District of Columbia
He was on time, courteous, efficient, speedy, and advisable about certain things to be aware of for future service. Please send him every time, as he seems to be very much aware of the mechanics and engineering of my car more so than all the others who have serviced it...He pleases me utmost. in the professional service I requests.
Chevrolet Malibu - Oil Change - Washington, District of Columbia
EXCELLENT experience!!! Simon is friendly, courteous,and professional. Very customer oriented. He answered my questions with knowledgeable replies which made me feel comfortable. He also came out on his day off to work on my car. Which speaks volumes on how he strives to take care of his clients. Definitely will book him for any car problems or services I need in the future.

John

21 years of experience
650 reviews
John
21 years of experience
GMC Sierra 1500 V8-5.3L - Oil Change - Howey In The Hills, Florida
John was great, Knowledgeable, professional and got straight to work. He was on time and finished expeditiously.
Kia Sportage - Oil Change - Orlando, Florida
John was professional and very nice. He also explained some issues I was having with my car and what I should and should NOT do. He was able to wxplain it to me without being condescending in any way. I will request John every time going forward!

Shawn

13 years of experience
379 reviews
Shawn
13 years of experience
Nissan Altima L4-2.5L - Oil Change - King Of Prussia, Pennsylvania
Shawn was awesome!!!! Professional, knowledgeable, kind, courteous and very thorough. Please thank him for me.
Lexus IS300 - Oil Change - Norristown, Pennsylvania
Shawn is always professional, honest, easy to talk to and always on time. I've never had an issue working with him and will continue to book him as long as he's available.

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

Related articles

Symptoms of Bad or Failing Oil Cooler Lines
Common signs include low oil levels, crimps or bends in the hose, and oil puddles under the car.
How Long Does an Oil Pan Last?
The The oil that is contained in your engine is helps to lubricate all of the moving parts that your motor has. Making sure that the oil stays at the right levels should be one of the top concerns that...
How to Find the Source of an Oil Leak
Oil Oil leaks are a very common problem that affects many car owners. Virtually all modern engines use some sort of oiling lubrication system, and a compromise in the sealing of this system will result in an oil leak. Whether...

Related questions

Volume of oil for new AC compressor and dryer?
The new compressor may have a sticker on it or there may be information within box of the compressor indicating the correct oil type and amount to use. The drier should have one once it's put in. Most new compressors...
I drove my car about 50 miles without the oil cap it started rattling and cut off and now it wont crank
Having driven that far with no oil cap, it is likely that the engine oil level ran low enough to cause engine damage, possible seizing the engine. If that is what happened, adding oil will not help once the engine...
Regarding engine flush 2015 Hyundai Santa Fe
Hi - by "system flush", I understand you to mean a flush treatment (https://www.yourmechanic.com/article/what-does-it-mean-to-flush-fluids-in-a-car) of the engine proper, to clean out oil sludge. An oil flush sometimes uses a product called Seafoam to do so. An oil system flush with...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (844) 997-3624 · hi@yourmechanic.com