Changing the Oil in a 2003 Subaru Legacy

  1. First, jack up your car and secure it using jack stands. This makes getting under the car (where most of the work is done) a lot easier!

  2. Next, open the hood and unscrew the oil filler cap. It's probably a large yellow cap with an oil symbol on it.

  3. With an oil drain pan underneath your car, locate the oil drain plug and slowly unscrew it. As you're unscrewing it, gently push it inwards so that oil doesn't immediately start flowing out. When it's completely unscrewed, release the drain plug from its seating and ensure that the oil is draining into your oil drain pan.

  4. When all of the oil is drained (it will likely still be dripping a little, but it's not necessary to wait for that to stop), clean off the oil drain plug area of the engine, and then re-install the drain plug. This should be tightened firmly, but not overtightened.

  5. Now, the next step before filling it with new oil is to replace the oil filter. Using an oil filter wrench, unscrew the oil filter. There will still be oil inside of the filter, so be careful as you're unscrewing it. If necessary, unscrew it part of the way, let some of the oil drain out, and then continue the rest of the way. As you take it off, make sure the open end of it is facing upwards in order to keep the oil inside from spilling out.

  6. Now you can install the new oil filter. Double check that it's the same size and correct fit for your car by comparing it with the old one (even better, check its compatibility by looking up the unique coding on the box or filter online). Before you screw the new filter on, lightly coat the rubber gasket of the filter with oil—this will help it seal. Now, screw it on by hand. As soon as the rubber gasket makes contact with the metal of the engine, tighten the filter 3/4 of a turn to 1 full turn. Do not overtighten, as this can cause oil leakage.

  7. You can now refill the engine with brand new oil! A 2003 Subaru Legacy 2.5L engine can hold approximately 4.2L of oil total. However, it is important to note that whenever you drain the oil for an oil change, there is still some oil left in certain parts of the engine that cannot be fully drained. Because of this fact, you should not have to put 4.2L of oil into the engine for an oil change. Instead, start by putting in about 3L of oil, wait a few minutes for that oil to find its way through the engine, and then check the oil dipstick. If it's below the Low line or right around it, add a little more oil (300ml at a time), wait, and then check again.

  8. Once the dipstick is close to the Full line, tighten the oil filler cap back on and start the engine of the car. Let it run for a few minutes, or take a quick drive around the block. Park it and then check the dipstick again. If the oil level has gone down, add some more oil, wait, and then check again. Repeat until it's just below the Full line!

  9. You have now successfully changed the oil in your 2003 Subaru Legacy! Over the next 3-5 days, make a point to check the oil every single day to ensure that you have enough oil in your engine. If after 3 days the dipstick gives you the same reading, go back to checking it once a week or every time you fill up gas!