Changing Your Engine Oil

Use Ramps or Jack Stands
Drain Plug & Filter
Draining the Oil
Putting in the New Oil
Checking the Oil Level

What you will need: 4 or 5 quarts of the recommended grade of oil your owners manual calls for (5W30, 10W30), a new oil filter, an oil filter wrench (this is to remove the old filter. The new filter should only be tightened by hand), a drain pan to catch the old oil, a wrench or ratchet and socket the size of the oil drain plug, a new PCV valve (these should be changed when the oil is changed), a set of car ramps or a jack and jack stands if you can't get under the car, a funnel, and LOTS of rags.

Pull the car on the ramps, or jack it up and place the jack stands under the frame, then let the jack down. Never climb under a car supported only by a jack. If you aren't sure where the car's frame is, you need to have someone show you. Putting the jack stands in the wrong location can punch a hole in thin sheet metal.

Locate the oil drain plug. It will be on the bottom or lower edge of the oil pan. Place the drain pan under the plug, then loosen the plug with a wrench or socket. Once the plug is loose, remove it slowly by hand. This is where you get dirty. The oil will start flowing out before you completely remove the plug, but taking the plug out quickly will cause a 'burst' of oil to come out in a stream, and probably miss the drain pan.

Once the oil drains, locate the oil filter, place the drain pan under it, and use the filter wrench to remove it. There are a few different types of oil filter wrenches. Which type you use will depend on where the oil filter is, and what other items are around it that may obstruct your access to the filter. Once the filter is loose, remove it by hand. Unlike the drain plug, there won't be a 'gush' of oil at first. What there will be is a slow stream of oil that may get on other parts of the engine or suspension. Engine oil can actually damage some rubber parts, so be sure to clean any rubber parts it gets on (thus the need for LOTS of rags). The oil filter will have some oil in it, so be sure it's over the drain pan and tip it over (where the oil will pour out of the hole). It's illegal to dispose of engine oil in the trash, so you'll need to take it to a disposal site. Most garages can dispose of it for you, but there may be a charge.

When the oil has completely drained (about 10 minutes or so), replace the drain plug. Tighten it by hand, then 1/2 turn with a wrench. Don't over tighten the drain plug. Next, take out the new oil filter, open a bottle of fresh oil, dip your finger in it, and coat the rubber gasket on the oil filter. Now install the new oil filter by hand. If you can't get a good, snug fit with your hand, once you feel the filter tighten up, you can use the oil filter wrench to turn it 1/4 turn, but no more. If you over tighten the oil filter it will damage the rubber gasket.

Now go to the top of the engine, locate the oil filler cap. This should be on the valve cover or on a tube sticking out of the engine. Remove the cap, insert the funnel, and add the correct amount of oil. This will be listed in your owners manual, and will usually be between 4 and 5 quarts.

Once you've added the correct amount of oil, look under the car for leaks. If the drain plug is leaking, tighten it until it stops leaking, then give it about 1/4 of a turn. The oil filter won't be leaking yet, because there won't be any oil in it. Lower the car and start the engine, or back it off the ramps if you used them (if you check the oil before you start the engine, it should read over full by 1/4 to 1/2 a quart. This is because there is no oil in the oil filter yet). With the engine running, look under the car at the oil filter and watch for leaks. If it is leaking, shut off the engine and tighten the filter. Start the engine again, and again check the filter for leaks. If it's still leaking, you'll need to tighten it a little more. If it's leaking more than it was when you tightened it, you've damaged the rubber gasket and you will need to have someone take you to the store to get another filter. Don't drive the car if oil is leaking from the filter. A damaged oil filter gasket will get worse very fast, and you could end up pumping all of the oil out of the engine before you get to the store. If there's no leaks, let the engine run for a minute or two. Keep checking for leaks during this time. If there's no new leaks, shut off the engine and wait about five minutes for the oil to drain into the oil pan before checking the oil level.

Since the oil is new, it will be clear and may be hard to see on the dip stick. You may have to wipe the dipstick off and check it again if you can't tell for sure where the oil level is.

Changing your oil is a relatively easy task on most cars, but it's a dirty job. Also, some engines have the oil filter located in a very difficult location to get to, especially if you're laying on your back under the car. Whether or not you decide it is worth paying someone to change your oil for you or doing it yourself is an individual choice. If you can do it yourself, you will of course save money. Either way, whether you change your oil yourself, or have a shop do it, you should change your oil at the recommended intervals in your owners manual. This is usually every 3000-3500 miles. While some oil manufacturers have claimed that their oil can last 10,000 miles, it is generally best to use the same oil for no more than 5000 miles to maximize engine reliability and efficiency over the long term. Even synthetic oil needs to be changed regularly.

Oil Filters

NEVER change you oil without changing the oil filter. As the name implies, an oil filter filters the oil as it travels through your engine. This means it's trapping dirt and other items that can harm your engine. Because of this, the filter is naturally going to get dirty and need to be changed. In fact, it's more important to change your oil filter than it is to change the oil itself. This isn't to say you can just change the filter and not the oil. While this would help keep the oil in your engine clean, it does nothing to replace the additives the oil loses over time. No garage should ever be willing to change your oil without changing the filter as well. Be wary if any shop you take your car to would ever suggest not changing the oil filter.

The oil filter is usually a metal 'can shaped' item located near the bottom on the side of the engine, but on some newer cars the filter is not encased in metal. These filters are a 'dropped in' to a permanent housing that is accessible from the top of the engine rather than from underneath (see center image).

Name brands: When it comes to oil, I use Valvoline Pure Synthetic or Mobil 1 Pure Synthetic, but all motor oil has to meet the minimum SAE (Society of Automotive Engineers) standard to be sold to the public, so the brand of motor oil you choose is up to you. Oil filters are a different matter. Without naming names, I've taken a variety of cheap filters and name brand filters and cut them all open. What I found was that the cheap filters had about half as much filter surface as the name brand filters. I also noticed that the general construction of the cheap filters were what I consider sub-standard compared to the name brand filters. It was very difficult to tear apart a name brand filter to inspect it. The cheap filters on the other hand practically fell apart. My recommendation; stick with the name brands like Valvoline, Mobile 1, Fram, etc. when it comes to your oil filter. The extra few bucks you'll spend on them is a lot less expensive than repairing or replacing a damaged engine.

Questions & Answers

Why does my engine need oil?
Oil is the life blood of you car. Your engine has a number of metal components inside of it that move against each other. Engine oil lubricates these metal parts to help prevent them from wearing out.  Without oil, the engine will seize up in a matter of minutes. This will cause permanent damage, especially to bearings, and the repair bill will be very expensive.

What causes oil leaks?
Engine oil wears out over time, but it doesn't disappear without a reason. An engine is made up of various pieces. These pieces are made of steel, iron, and aluminum that are bolted together. Between these different pieces are gaskets. It's these gaskets that keep oil and water from leaking out where the metal parts are bolted together, and it's these same gaskets that can harden and crack over time and cause leaks. Sometimes leaks are not from wear, but from some type of damage or flaw in the gasket that causes it to leak. Other than a leaking gasket, engine oil leaks can be caused by cracks or warps in one or more of the metal parts, especially the aluminum parts. Most of today's engines use aluminum for the head or heads, and aluminum is sensitive to heat. Aluminum will warp much faster than cast iron if the engine overheats.  Another possible cause is damage to the oil pan. If you have run over an object, it's possible the object was thrown into the oil pan and punctured it.  The labor cost in replacing some gaskets or an oil pan can be expensive... but replacing an engine is even more expensive. Leaks don't fix themselves, so if your engine is leaking oil or coolant, it will only get worse. If the oil level is constantly low, or there are oil spots on the ground where you park, you either need to inspect the engine for leaks, or take it to a garage and have them inspect it for leaks.

Why do I need to change my oil?
Even though oil molecules technically never break down, the additives in the oil does. This is what causes the oil to thicken over time. Also, the environment inside an internal combustion engine is hostile. Temperatures regularly exceed 200 degrees, and the very act of combustion creates internal gasses within the engine block. These gasses contaminate the oil. Oil also gets dirty over time. Even though it goes through a filter, some small particles of dirt get through the filter. They have to, because if the filter were so dense that it trapped every bit of dirt, the oil couldn't flow through it.

What oil do I use?
Check your owners manual to be sure. Unless you own a pre-1980s vehicle, the owners manual will most likely recommend you use either 5W30 or 10W30. Pre 80s vehicles may require a 10W40 oil depending on the engine size and mileage.

Is there a difference between engine oil and motor oil?
Most people use the term motor oil when talking about engine oil, but it's the same thing. Technically, a motor is an electronic device, such as the electric motor that starts your car, which is why you may hear mechanics use the term engine rather than motor when referring to the engine in your car.  NOTE: There are lubricants at your auto parts store that aren't engine oil. These include oils differentials, manual transmissions, or other parts of a vehicle. Be sure you only use oil designed for use in your engine and not some other type of lubricant.

Is automatic transmission fluid, power steering fluid and engine oil the same thing?
NO. Transmission fluid and power steering fluid are not oils. They are hydraulic fluids, not lubricants. Putting these, or any other hydraulic fluid in your engine will damage it, just as putting engine oil in your automatic or manual transmission, or your power steering fluid reservoir, will damage those items.

What do the numbers 5W30, 10W30, and 10W40 mean?
Getting into detail and trying to explain more about what those numbers really mean can be very confusing, and very time consuming, and again, to fully explain it is more involved than we'll be getting into in this article. In the simplest terms, they're like a rating system for the viscosity of the oil at different temperatures. Using the 5W30 as an example, 5 is the weight of the oil when it's cold, and 30 is the weight of the oil has when it's warm. Years ago people would use a heavy oil in the summer, like 10W40, and a lighter oil in the winter, like 10W30. Today, that isn't necessary. Oil technology has come a long way since the '50s and '60s. Some people will also use a heavier oil if they had an oil leak to try and slow the leak. This is a bad idea, since a thicker oil will do more damage to the engine at start up and in colder weather, and the leak will still persist.

What about synthetic oils?
Synthetic oils really are better because they reduce more friction at start up than oils made from fossil fuels. When your engine is shut off, the oil is sitting in the pan instead of flowing through the engine, so it's not lubricating the engine. Because of this, your engine suffers the most damage when you first start it. Theoretically, an engine would last 10 times longer if it were never shut off. Notice I said 'theoretically'. There are other problems that arise when an engine is running, especially at idle.

When properly maintained, including a regular steam cleaning of the engine and undercarriage to remove road debris, most engines should last 100,000 miles or more without any leaks. If your car doesn't have at least 100,000 miles on it and one or more your fluids are always low, you need to take it to a garage and have them find out why the fluids are leaking, and repair the problem or problems.

Remember, leaks never fix themselves, and they always get worse over time.


Tips

1. Buy a repair manual for your particular car. Owners manuals are nice, but they don't cover anywhere near as much information as a repair manual does. This is why repair shops usually have a full library of repair manuals on hand.
2. Track your mileage and fuel economy. Not only will you learn to save fuel and drive more moderately, but you will notice if something changes about your fuel efficiency. A drop in miles per gallon can signal a maintenance problem. Track your oil changes in your mileage log, too.
3. In the trunk (or whatever storage are the car has) keep a few rags for checking the various fluids, a tire pressure gauge, and a flashlight specifically for maintenance uses. Unless you have free roadside assistance, it's also a good idea to keep a spare serpentine belt or fan belts, and the tool or tools required to change them. If you have room, carry a spare upper and lower radiator hose, new clamps, and two gallons of 50/50 anti freeze. Even if you do have free roadside assistance, it never hurts to have these items on hand... just in case.
4. Check your spare tire to make sure it's properly inflated. Having a spare tire doesn't do any good if it's flat.
5. Look for drips where you park. Small oil, coolant or other fluid spots means something is leaking and needs to be repaired.