How to change engine oil

Changing the oil in your engine is one of the basic items of auto maintenance that should be performed regularly to prevent internal wear to the engine and keep it running for years to come.  Make no mistake - neglecting oil changes will eventually lead to premature engine death.

Oil is required in the engine to lubricate parts that are in contact with each other.  Pistons, camshafts, valves, etc.  Without clean oil these parts start wearing away at each other, heat builds up, and in the worst case of no oil the pistons can weld themselves to the cylinders.  An oil change is *much* cheaper than a new engine.



When to change your oil

Follow the manufacturer's recommended interval.  Jiffy Lube's "3 months or 3,000 miles" is very aggressive and is aimed more at repeat business than what the car requires.  Most manufacturers these days recommend intervals of 5,000 to 7,500 miles or even longer.  Check your owner's or shop manual for your car's recommended interval.

The actual interval required can depend on the type of driving you do as well, for example if you do mostly short trips that don't heat up the oil enough to burn off condensation you'll need to change the oil more frequently. If the car is driven very infrequently, the oil should be changed after a certain amount of time due to the amount of condensation that builds up in the oil.  For example, a car only driven 1000 miles/year might still need an oil change once or twice a year.

Your car may also lose oil over time if it is leaking or burning oil.  Make sure to check the oil level periodically in between changes to make sure it doesn't get dangerously low.

What to buy

Oil comes in different viscosities (also called weight), which is a measurement of how thick the oil is.  The manufacturer will specify a certain type that the engine was designed for.  Stick to this viscosity. Usually it will be specified right on the oil filler cap.  If not, check the owner's manual.

This oil cap lists 5W-20 as the recommended oil type.

What usually isn't on the oil cap is the amount of oil required.  Check the manual for this as well (or Google, or ask at the auto parts store).  Engines can require anywhere from four to six or more quarts depending on the engine size.  It is very important that you don't under fill or over fill the engine with oil, so make sure you know how much oil you expect to put in before you start.

Engine oil usually comes by the quart or in five quart jugs.  While you're picking it up, make sure to get a replacement filter as well.  The filter removes small particles and junk that get into the oil.  The auto parts store will need the make and model of your car to get the appropriate filter for you.

The washer on the drain plug will need to be replaced as well, so ask for one.  They can either be metal or plastic.  It's possible to reuse the old one but it's better to replace it.

What to drain the oil into

If this is your first time, pick up an oil drain pan.  The best ones to use are fully enclosed with a removable top to drain the oil in, and a spout to pour the oil out when recycling.  You can usually bring the oil back to the place you purchased the new oil from and have them recycle it.

An oil drain pan.  I like to keep a garbage bag around to keep it in
for transportation so I don't get oil in the trunk of the car.

For first timers, you'll also need an oil filler funnel to help put the new oil in without spilling.

Now you can get started!

Start by warming up the engine.  The oil will run out of the engine faster and will take more gunk with it than if it were cold.

Park the car in a flat area.

For most cars, you'll need to jack the vehicle up and put it on jackstands to get enough room underneath for the oil drain pan and access to the drain plug.

Open the hood, and remove the oil filler cap.  This allows air into the engine as the oil drains.

Remember where you put the cap, because they will grow
legs and disappear sometimes!

Climb underneath the car and look for the oil drain plug.  I finally bought a pair of coveralls for crawling around on my back, because even a clean garage floor seems to have plenty of dirt to stick all over my clothes.  If you don't want to lay on your back, you can get down on your hands and knees and peek under the car, but it will be harder to find and reach the parts.

Front left to right: Oil filter, drain plug, engine oil pan.

The drain plug will be somewhere on the oil pan at the bottom of the engine.

It's a good idea to put some cardboard down on the floor to keep oil from spilling on it.  Get it and the oil drain pan in place under the drain plug.  Make sure you remove the venting cap, if applicable, and make note of the direction the drain plug is pointing.  The oil will come out in that direction.

It's also a good idea to put on some rubber gloves at this point to keep engine oil off of your hands.  Break the bolt loose with a socket, then unscrew it with your hand.  When it comes loose pull it away quickly or you'll get a stream of oil all over your hand.  Keep in mind that if the car was fully warmed up, the oil will be very hot.  It's OK to let it cool a bit first if you've been driving the car.

Unscrew the drain bolt after breaking it loose.

Oil will come out very quickly, so make sure the drain pan is
in place. Note the direction the oil is headed - if not taken into account
you can easily overshoot the pan if not positioned properly and
make a big mess.

Wait for all the oil to drain out.  When it slows to a dribble, remove the oil filter.  Depending on the car, this may or may not be easy to get to.  Sometimes they like to put the filter in a spot that takes a contortionist to reach.  Either way, usually you can spin it off with your hands.  If not, you may need an oil filter wrench for some extra leverage.  In an emergency situation, you can hammer a screwdriver through the filter and use that to spin it off.  Place the filter upside down on top of the drain pan.  Some have a spot specifically for the filter.

If you're lucky, the filter will spin right off.  If it doesn't, you may
be able to develop tons of character.

Filter draining on top of the drain pan.

Get out the new filter, and apply a coat of fresh oil to the rubber seal.  Then, spin it on in place of the old filter.  If you want the filter to come off easily again, spin it on until it's snug, then go another 1/4 turn.  Do not crank it on with a wrench!

Tip: Make sure the old gasket has completely come off with the filter and there is no residue stuck to the engine.  Wipe it clean with a rag and if it's not clean polished metal, clean it up with a razor blade.  Also, make sure the gasket on the new filter is still there upon installation.  Many years ago my brother installed a filter whose gasket had fallen off, and oil sprayed everywhere once the car was turned on.

A coat of oil on the gasket will help prevent the filter from leaking.

Spin it on hand tight, first snug then 1/4 turn.

Now replace the washer on the drain plug and screw it back in.  At this point I like to wipe the drain pan and filter clean with a paper towel.  Tighten it hand tight with a socket wrench.  Again, don't go use He-Man strength or you could risk stripping the threads or making it hard to remove in the future.

It's a good idea to replace the drain plug washer.  Some people will replace
the entire bolt/washer each time.

There is nothing wrong with using a torque wrench here, but most people
do it by feel.  Make it tight, but keep in mind you do *not* want
to strip these threads.

When you are sure the filter and drain plug have been tightened correctly, lower the car back down off the jack stands.  Place the funnel in the oil fill hole, and start pouring oil in.

After putting about a quart of oil in, I like to peek underneath the car and make sure nothing is leaking.

Since it is important not to overfill the engine, I like to fill with one quart less than is called for by the manual.  If you're using quart sized containers you can count the containers, if you're using a five quart jug there is a window on the side the check how much oil is left in the container so you can figure out how much you've put in so far.

Check the oil level using the dip stick, and make sure it just barely touches the bottom.  Now you can pour the oil in 1/4 or 1/2 quart at a time, and check the dipstick to make sure you're right on target.  The dipstick generally has two markings.  The top marking is "full", the bottom marking usually means one quart low.

Dipstick shows the oil level is up to the second dot,
indicating it is topped off properly.  The fresh oil is hard to see.

Checking the oil level with fresh oil can be hard because brand new oil is almost colorless, as opposed to used oil which can be very dark.  You may have to turn the dipstick just right in the light to see it.

Once you're filled up, put the oil cap back on, shut the hood, and you're good to go! As the last final precaution, after you start the car and back out of the garage, make sure you don't see any oil leaking out onto the ground.  Better to find out now than miles down the road.