Regularly changing your car's engine oil and filter is one of the most important things you can do to keep your car running well. Over time your oil breaks down and your filter becomes clogged with contaminants. Depending upon your driving habits and type of vehicle, this may take as few as 3 months or 3,000 miles, or be as long as 20,000 miles or 24 months (consult your owner's manual for service intervals). Fortunately, changing your oil is both easy and inexpensive. This guide will help you to learn how.
The picture to the right shows Car oil that has not been changed for 10,000 miles.
Gather all the necessary supplies and equipment. Under your car with all the oil out is not the time to discover what is missing. It will help to have everything close at hand. (Caution: take great care when working with a hot engine.)
Before draining out the old oil, you may want to lift the bonnet of the car and open the oil filler cap on the top of the engine. This will help the oil drain easier because air can flow in as the crankcase drains. Locate the drain plug on the bottom of the oil pan. It is normally towards the back of the engine at the car to catch oil runoff. As the oil comes out of the pan at an angle, it can be tricky to catch, and may land on the ground. If this includes your driveway, you will want some newspaper or a drop cloth to catch it, or you risk an oil stain on your driveway or garage.
Loosen the plug counter-clockwise using the proper sized socket (or wrench). The fit is especially important if the bolt is tight, which it shouldn't be. If you need more leverage, an extension such as a pipe segment on your ratchet handle can help. If this type of "breaker-bar" arrangement is required it was way too tight. You should also remove and replace the circular paper (or felt) drain plug gasket, but a metal washer can be re-used if in good condition. Be careful not to drop the plug in the oil, it's a messy job trying to find the plug in the black stuff. If you do drop it in the pan, you can easily find it with a magnet. Ideally, use the type that is at the end of an expandable rod.
Another easy way to "save" the drain plug is to use a funnel with a bit of screening in it. Catch the plug as it falls out. You can then pull the funnel out of the way of the stream and set it to one side.
Some vehicles (such as BMW, Mercedes, newer Volvos, etc) may have a filter element or cartridge as opposed to the simpler spin-on type. They require you to open the cap of a built-in resevoir and lift out the filter element itself.
Locate the filter assembly. This can be a tough part. Filters are not put in a standard position, and they can be on the front, back or side of engines. Look at the filter you purchased to replace the old one and look for something similar. Once you have located it, remove it from the engine. This can be tough, and often seems too hard. Once you get a good grip slow and steady twisting can sometimes get it to begin to spin. If you can't get it off by hand, use an oil filter wrench. Keep trying. It will eventually come off. There will be oil in the filter, so be careful not to spill it and have a pan underneath to catch the drips.
When removing the oil filter, make sure that the rubber gasket ring comes off with the filter. If you don't and it sticks to the car, the new filter won't seal properly and will leak.
When installing the new filter, remove all packaging, then dip the tip of your finger in the new oil and smear it on the gasket ring of the new filter. If you use the old oil, it may contain buildup that will wear away between the gasket and the car and eventually become a leak.
You might pour some oil into the filter prior to installing it. This can reduce the amount of time your car takes to regain proper oil pressure. If your filter is mounted vertically, you may be able to fill it almost to the top. If mounted at an angle then a little oil will spill just prior to spinning the filter on but that will not amount to much. Garages don't tend to pre-fill filters because it takes time, and for them time is money.
Replace the drain plug on the oil pan. Don't forget to install a replacement gasket or washer. Start threading it with your fingers so as not to cross the threads, and it should be snug, but no need to be super-tight.
Carefully screw on the new, lubricated filter, being careful to not cross the threads. With the paper cartridge filters, they will always come with at least one o-ring, sometimes as many as four different ones. Make sure to replace all of them to ensure that they will not leak. The filter will generally say how tight to tighten it. Go until the gasket touches, then however far it says it should be. This is usually 2/3 or 1/4 of a turn after the gasket touches but could be more. Read the specifications on the filter or box it came in. Using a cap wrench can make it easier to install per specs if the filter is in a difficult to reach location.
Add new oil to the car at the fill hole. The amount you need is in the owner's manual, usually listed under "capacities". Don't always rely on the dipstick for an accurate measurement; it can be off, especially if the engine has just been run (the stick will read low because there is still oil in the galleries). If you want to check the stick accurately, just check it first thing in the morning, parked on a level surface, when it's cold and settled.
If you hold the bottle with the spout on top, as shown, it will pour more smoothly, without bubbling.
Replace the fill cap, check around for tools and close the hood.
Start the engine, watching to be sure the oil pressure light goes off after start-up, and be sure to look under the car while the engine is running (put car in park or neutral with the parking brake on) to check for any drips. If the filter and drain plug aren't tight, they may leak slowly. Run the engine for a minute or so.
An oil pan and socket wrench.
The oil drain plug.
Removing the drain plug gasket.
The oil filler cap.
Remove the filter, using a filter socket or filter wrench if necessary.
Tip the filter into your pan to drain the contents.
Lubricate the gasket on the new filter with new oil.
Replace the drain plug.
This would be a good time to wipe any debris or buildup off the surface where the gasket will seat.
A funnel will help.
- Be sure you have purchased the right filter and have all the tools you need before starting. It's a pain to have to run back to the store in the middle of the job, especially since you won't be able to use your car.
- It's helpful to have a friend who has done this before around for assistance.
- To avoid getting oil all over your arm when removing the drain plug bolt, apply inward force (as if you are trying to push the plug back into the hole) while removing it. When you know that bolt is fully unscrewed, quickly pull it away from the opening. If you're lucky only a few drops will get on your hand. Tie a rag around your wrist when you remove the oil plug. Oil might get all over your hands, but it won't go all the way down your arm, making it a messy clean up. Also, have pumice or citrus hand-cleaner, or consider using disposable gloves to keep your hands perfectly clean. Latex rubber will decay quickly in oil, so nitrile or another material is a better choice.
- For a very stubborn filter, using a hammer and a large screwdriver as a sort of "chisel" can push the filter counter-clockwise. Be advised: once you punch hole in this thin filter wall, the engine cannot be started until it's replaced.
- There are some oil drain valves on the market that replace your normal drain pan bolt. These can make oil changes much more convenient and can reduce the amount of mess you make.
- To avoid spilling too much oil as you remove the filter, wrap a plastic bag around the filter, which will catch any oil that escapes as you remove it. Before disposing of the old filter, it is best to get all possible oil out. This can be done by suspending it upside-down on a heavy wire mesh set across your oil catch basin. As a last step, taking your time (because warm used oil is thin, ie, low viscosity), pour it through a big funnel into gallon jugs. They can be coolant, windshield-washer fluid, anything with a secure screw cap. Leave a few inches of room at the top. Don't allow these containers to sit in sunlight too long, the plastic can get very brittle.
- Remember to always make sure that the oil you use fulfills the car manufacturer's requirements as stated in the manual. Be sure to use the oil specified in the owners manual as to viscosity. That's the number that looks like "10W-30". A lower "W" rating means the oil is formulated to flow better in cold. Below freezing, a 5W oil is preferred. Below 0°F (-18°C), a synthetic 0W oil is worth considering.
- Draining your oil with the engine still warm can speed up the draining process. Be careful not to let the hot oil get on your skin.
- Taking your car into the shop to get the oil changed is never a bad idea. It is inexpensive and allows them to check for any other problems that may arise in order to prevent a large repair bill later on.
- Spills happen. To avoid fines or polluting the environment consider having a green, eco-friendly oil absorbent product on hand in case you spill some oil. They will absorb oil and most other liquids like gasoline or paint and will keep your garage and driveway clean. Kitty litter or clay-based products are not effective solutions for this. You can find a wide variety of eco-friendly oil absorbent products online. They are extremely absorbent, easy to use and renewable.
Recycle your oil, or store it if you have to. Dumping it on the ground is illegal. Your local auto store or garage will take your used oil for free, in most cases. Many of them heat their garages with waste oil so they are happy to get it.
- Instead of lifting the car, you can park over a trench or ditch or with two wheels up on a curb. Be sure to take every safety precaution while doing this (use the emergency brake, block the wheels, make sure the tires are completely stable on the ground, etc.).
- It is unsafe to work on a car that is still on a jack. Instead, use jack stands (never cinder blocks) and do the whole thing on a level concrete surface.
- Be careful not to burn yourself! Your engine, the used oil inside it, and other parts of the car can stay hot enough to burn you for a long time after you turn the ignition off.
- Refer to your owner's manual for jack/lift instructions; improper jack placement can damage your car badly.
- This how-to is not meant for all cars, and certainly shouldn't be your only source of information. Always consult your owner's manual for manufacturer's recommendations when determining your maintenance schedule.
- Don't get the oil inlet confused with the transmission fluid inlet. You can ruin your transmission if you put oil in it.
- If you don't use the correct wrench on the drain plug bolt you run the risk of "rounding it off" (destroying the head of the bolt).
- Do NOT over or under-tighten the new filter. Always tighten it to the manufacturer's specs either by hand or with a cap tool.
- Don't overfill; that can cause foaming or spills.
- Be careful with additives. Many of these products are more marketing than substance, and some can void your warranty or harm your vehicle. Check with the service people at your dealership first.
- Check with your owner's manual on selecting the correct weight (0W-40, 10W-30 etc) and type of oil (mineral, synthetic). Many high performance vehicles (especially those with turbochargers) require synthetic oil of a specified weight. Running mineral oil or the wrong weight may cause damage.
Things you will need:
- Oil (check your owner's manual for specific weight and quantity needed). Most cars use 4-6 litres. Also, make sure you use oil that meets the API performance rating for your vehicle. Most vehicles made since 2004 require rating "SM", which is better than the oil that was available when older cars were made. Always use the newest and latest spec oil available.
- Socket wrench (for European or Japanese cars you will likely need a metric set).
- Oil filter (contact your local auto parts store for specific model of filter). Expensive ones do not clean oil any better. The ones that have a grippy coating are easier to install and tighten.
- Oil filter wrench. There are different size oil wrenches available depending on the diameter of the filter. The expensive one that is double articulated is the surest one to use.
- A way to get your car off the ground (ramps or a jack & jack stands work best). NEVER get underneath a car supported only by a jack! This is extremely risky. Always use a jack stand. 2 ton jack stands tend to run between $20-$25 at your local auto store.
- Something to catch the used oil in, and a funnel and sturdy gallon jugs to transport it.
- Oil rags or paper towel.
- Some vehicles require you to remove top or bottom panels, which might require additional tools.