Oil Changes - Reasons for Oil Changes in Cars.

Oil Change

Oil changes are very important for maintaining the life of your engine. By changing the oil you remove contaminants that have become part of the oil. Think of it this way, if I gave you a large lake to drink out of would you want fresh water to flow into it or would you rather drink stagnant smelly water. Now you know how your engine feels.

Checking Oil Level

Park your vehicle on a level piece of road or driveway. Pop open the hood and locate the dipstick. A dipstick is a long (several feet long usually) piece of thin metal with a loop or hook at the top. It lives inside of a tube attached to your engine In modern cars the hoop or hook usually has a piece of colored coded plastic (Red, Yellow, Green etc.) on it to make it obvious to see. A dipstick reaches down into the oil pan and shows you how much oil is in the oil pan.

Have a napkin or cloth in hand as you will need this to wipe the dipstick. Pull the dipstick out, wipe it with the rag/napkin, put it back in all the way and then pull it out. Look at the bottom of the dipstick and you will see makings. Look at where the oil is on the markings and this will let you know if you need to add Oil. If the Oil is between the low and the high mark then you are okay and do not need to add oil.

How to change the oil?

You will need either ramps of jack stands to support the vehicle, old rag to soak up stray oil (and oil dry or kitty litter if you mess up bad) wrench to undo the oil plug, wrench to undo the oil filter and an oil tray to catch the oil when you drain it. Remember to catch it. Oil running about is not good for the environment. That is why it was called the Gulf Coast Oil Disaster when that well leaked.

Find a level piece of solid ground and raise the part of the vehicle with the engine in it (front or back) off the ground by either driving it up the ramps you have or lifting it with a jack and placing the jack stands on part of the frame under the car. With jack stands, lower the jack so that the car rests on the stands and is not supported by the jack.

NEVER go under a car that is supported only by a jack.

When using ramps, be sure to apply the emergency brake after the car is up the ramp and block the wheels that are not on the ramp in such a way that if the car starts to role back down the ramp, the blocks will stop it. If you are not practiced at driving up ramps have a human spotter stand to the side and give you directions.

When using jack stands, be sure to apply the emergency brake and block the wheels as for ramp usage.

In all cases, try to shake the car a little before going under it to ensure that it is secure when up in the air. Better the car fall down now while you are not under it.

If the engine has been running for a while, the oil will be hot so be careful.

Put a piece of cardboard under the car and put the oil collection tray on top of that. The cardboard will catch any oil that escapes.

Crawl under the car and locate the drain plug in the Oil Pan. See our Oil Pan section for an image of what an Oil Pan looks like.

Position the oil tray so that it will catch the oil as it comes out of the Oil Pan. Note that the oil will not come straight down but come a little way out before it hits the ground. As the oil comes out, this angle will change as the pan has less oil in it, so if you are catching the oil in a narrow necked container be prepared to move it.

NOTE: Depending on your engine, you may have to catch anywhere from 3 quarts of oil on up (Semi Truck engines can have 20 quarts). We just mention that so you are aware of the size of container you will need.

Loosen the Oil Plug in the Oil Pan and be prepared to adjust the oil tray to catch the oil.

Let the oil drain into the Oil Tray.

While it is draining you can look to find the oil filter. It will be close to the side of the engine.

Oil filters twist off and sometimes can be loosened by hand but usually require a big wrench (like a large pair of pliers).

Depending on where the Oil Filter is, it will most likely be full of oil when it comes off and will also drain some oil down the side of the  engine so be prepared to catch it in the oil tray. 

Putting a new Oil Filter on is done by hand. First wet the seal of the new Oil Filter with some oil on the end of your finger (with protective gloves on). Then twist until the Oil Filter seal touches the end of the Oil Filter mount - should look like the Oil Filter is all the way on. Then twist the oil filter a final 3/4 of a turn.

Once the oil has finished draining out of the Oil Pan (becomes a slow drip), replace the Oil Pan plug and tighten with your wrench.

Now you need to replace the oil in the engine. To do this, open the hood of the car and locate the Oil Fill cap. Add the amount of oil that is recommended for your engine and then replace the Oil Fill cap.


Lower the car back to the ground either with your jack or rolling back down the ramps.

Run the engine for a minute, turnoff and then check the Oil Dipstick to see if you have enough oil in the engine. Add as needed.

Old oil and sometimes the filter can be recycled at autopart stores.

When to change the oil?

1 - 3 months

If you do a lot of short drives around town then the 3 month rule will probably be best as you are not heating the oil up enough to help keep it clean.

2 - 3000 miles

Like the 3 month rule the 3000 mile rule has been around for a while. If you drive on the freeway a lot then you could easily double this especially with the new synthetic oils available now. If you are doing just general driving in town and a little bit of freeway then the 3000 mile rule probably applies.

3 - Freeway Driving

Engines love the freeway driving of being run at a constant RPM for miles on end. As stated before if you do this a lot then you could easily go for 6000 miles between oil changes if you are using a good oil.

4 - Use your nose

Smell the end of the dipstick. If the oil smells burnt or like gasoline then it is time to change.

5 - Use your eyes

On level ground pull out the dipstick and clean it off, stick it back in and then pull it out and check the level. If it is low now would be a good time to consider an oil change but keep track of how often it gets low as you may have a leak. Also look for the oil being dark - (black in color) as this suggests it is very dirty.

Don't Forget the Filter

Filters are important for keeping oil clean. When you change the oil you should change the filter.

How does oil get dirty?

1 - Gases from the engine

As the engine compresses gases and exhausts gases some get by the pistons and into the sump where the oil is. Over time these gases get absorbed by the car oil which changes the chemical properties making it not so good at doing what it is meant to do.

2 - Lubrication

Oil is everywhere in the engine lubricating parts so that they run smoothly. As parts wear little microscopic bits end up in the oil and overtime they can form a paste which ain''t no good for your engine.

3 - Overheating

If the oil gets too hot it starts to burn and form hard carbon particles. Remember Diamond is just hard Carbon and that is no pillow. These hard carbon particles will cause wear in no time if allowed to remain in your engine.

4 - Water & Humidity

Water vapor from hot summer evenings and snowy winter nights can end up working it way into the oil. This water vapor can be heated out by driving the car until the engine gage shows warm however short trips around town do not achieve this so the water which is bad for the engine remains in the oil.

Question or Solution not mentioned?
Use Auto Repair Forum to ask or answer questions about car and auto repair.

AutoLeak.com. All Rights Reserved Terms and Conditions Privacy Policy

Advertise your Auto/Car/Truck Repair Parts or Auto/Car/Truck Repair Business on this site.
Contact us at Advertising@AutoLeak.com
We have affordable advert solutions!
Act now to potentially reach thousands of unique people a month who are trying to repair/maintain their vehicles.