Acura RSX / Honda Civic Si (K20) Engine Oil and Filter Change
Introduction
This guide covers a complete engine oil and filter change on the 2002-2006 Acura RSX and the 2002-2005 Honda Civic Si (EP3). It applies to the K20A3 engine used in the base RSX and the Civic Si as well as the K20A2 used in the RSX Type-S; the two engines differ in drain plug torque and oil capacity, so both figures are called out where they matter. Regular oil changes are the single most important thing you can do to keep these engines healthy, and the job is well within reach of a first-time home mechanic. Running the engine for a few minutes beforehand thins the oil so it drains faster and carries out more contaminants. Read the whole procedure before starting, and note the drain plug torque was corrected during the discussion (29 lb-ft for the Type-S, not 33) and the Type-S fill quantity was clarified against the factory manual. Adapted from a community writeup by Ju5t Ep3 Pr4ct1c3 on Club RSX (https://www.clubrsx.com/threads/diy-oil-change.374897/), including corrections from the follow-up discussion.
Reference
Tools Required
- 3/8 in. or 1/2 in. drive ratchet
- 3/8 in. or 1/2 in. drive torque wrench
- 17mm socket
- Socket extension
- Floor jack
- Two jack stands
- Wheel chock or block of wood
- Oil drain pan or bucket
- Funnel
- Shop rag (brake cleaner optional for cleanup)
Parts Required
-
Approximately 5 quarts of fresh engine oil (see step on refilling for capacity by engine)
-
One replacement oil filter
-
One M14 aluminum crush washer for the drain plug
Safety Warnings
- ⚠ Support the vehicle on jack stands at the pinch-weld seams and never work under a car held up only by a jack; do not run the stands to their maximum extension.
- ⚠ Warm oil can scald. Keep hands and forearms clear as the drain plug and filter release.
- ⚠ The oil pan is aluminum. Torque the drain plug to spec with a torque wrench and use a fresh crush washer to avoid stripping the pan threads.
- ⚠ Verify the old filter gasket came off with the old filter. A doubled gasket will fail under oil pressure and spray oil.
- ⚠ Recycle used oil and filters at an approved facility; never pour them down a drain.
Step-by-Step Instructions
1 Warm the engine and open it up top
Run the engine for a few minutes so the oil reaches a warm but not fully hot temperature; warm oil is thinner, flows out faster, and takes more suspended debris with it. Shut the engine off, open the hood, and pull the dipstick and the oil filler cap. Removing the cap up top lets air in so the oil drains more freely from below.
2 Secure and raise the front of the vehicle
Set the parking brake fully and place a chock or block of wood against a rear tire so the car cannot roll. Raise the front using the factory jacking point built into the subframe, then support the car on two jack stands set at the pinch-weld seam locations on each side. Give yourself generous clearance to work underneath, but do not extend the jack stands to their maximum height. Always rest the weight on the stands rather than trusting the jack alone.
3 Drain the old oil
Slide the drain pan under the drain plug, which sits at the bottom of the oil pan and faces the rear of the car. Using the 17mm socket with the extension and ratchet, back the plug out along with its old washer. Keep your hand clear as the plug frees, because the oil escapes quickly and can be hot if the engine was recently running. Let it drain fully. Leave the plug out for now.
4 Remove the old oil filter
Turn the filter counter-clockwise to unscrew it from the block. A filter that was machine-tightened at a shop can be stubborn; a proper filter wrench or cap-style removal tool handles the ones a hand grip cannot. The filter sits above the axle, so oil tends to run down onto the subframe and brace as it comes free. Cutting a scoop from a washer-fluid jug and tucking it under the filter catches most of that spill. As the filter comes off, confirm its old rubber gasket came away with it and is not still stuck to the block sealing surface.
5 Prepare and install the new filter
Wipe the filter mounting surface clean and check again that no old gasket remains; a doubled gasket will blow out under pressure and make a large mess. Smear fresh oil around the new filter's rubber sealing ring so it seats without grabbing. Filling the filter partway with oil before installing helps reduce the dry interval at first start, though it is optional and messy. Thread the filter on by hand and snug it per the filter maker's instructions, which for many brands means a specified fraction of a turn past gasket contact; hand-tight until it stops turning is the usual target. Do not use a wrench to crank it down.
6 Reinstall the drain plug with a new crush washer
Fit a fresh M14 aluminum crush washer to the drain plug before reinstalling it. The soft aluminum washer is designed to deform against the plug as you torque it, sealing the joint and helping keep the plug from vibrating loose; skipping it risks a leak or damaged threads in the aluminum pan. Thread the plug in by hand first to avoid cross-threading, then torque it: 33 lb-ft for the base RSX and Civic Si K20A3, and 29 lb-ft for the Type-S K20A2. Because the pan is aluminum, use the torque wrench rather than guessing by feel.
7 Refill with fresh oil
With the funnel in the filler neck, add oil to the correct amount for your engine. The K20A3 in the base RSX and Civic Si takes roughly 4.4 quarts. For the K20A2 Type-S, the factory Helms manual lists about 4.8 quarts without a filter and 5.0 quarts with a new filter; the 6-quart figure sometimes quoted is the dry rebuild capacity, not a normal change. Have up to 5 to 6 quarts on hand, but add gradually and confirm the level rather than dumping in a fixed amount.
8 Lower the car, run it, and check for leaks
Raise the car off the stands, remove them, and lower it to level ground. Start the engine and let it idle briefly, watching the drain plug and filter for any weeping. Shut it off, wait a minute for the oil to settle, then check the dipstick and top up to the full mark. Because oil clings in the head and drains back slowly, rechecking after the car has sat gives the most accurate reading.
9 Clean up, dispose of the waste, and log the service
Wipe any spilled oil off the subframe and brace; brake cleaner cuts residue quickly. Take the used oil and old filter to an approved recycling or hazardous-waste collection point and never pour oil down a drain. Finally, record the mileage so you have a running history of the car's maintenance.
Pro Tips
- 💡 Bring the engine up toward operating temperature before draining; the warmer, thinner oil flows out faster and flushes more debris.
- 💡 Leave the drain plug out until after the filter is removed, since pulling the filter releases additional oil that would otherwise back up past the plug.
- 💡 A scoop cut from a round windshield-washer bottle, tucked under the filter, catches the oil that would otherwise run down the axle and subframe.
- 💡 For a filter tightened hard at a shop, a cap-style or strap filter wrench works when a bare hand cannot break it loose.
- 💡 Keep 5 to 6 quarts available for the Type-S, but set the level by the dipstick rather than pouring a fixed quantity.
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