🔧 Mazda3 - Engine Oil & Oil Filter Replacement

Changing the oil and oil filter on your Mazda3 keeps the engine lubricated and removes dirty oil that can cause extra wear. You’ll drain the old oil, replace the filter (the part that traps contaminants), then refill with the correct oil and reset the maintenance reminder.

Difficulty Level: Beginner | Estimated Time: 0.8-1.5 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a level surface and support the car with jack stands before going underneath.
• ⚠️ Let the engine cool 15–30 minutes; hot oil can burn you.
• ⚠️ Chock the rear wheels and set the parking brake.
• ⚠️ Wear nitrile gloves and safety glasses; oil can irritate skin/eyes.
• ⚠️ Do not get under the car supported only by a jack.
• Battery disconnect is not required for this job.

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🔧 Required Tools

You'll need the following tools for this repair:

• Floor jack (rated 2-ton minimum)
• Jack stands (rated 2-ton minimum)
• Wheel chocks
• Safety glasses
• Nitrile gloves
• Drain pan (at least 8-quart)
• Funnel
• 17mm socket
• 3/8" drive ratchet
• Torque wrench (3/8" drive)
• Oil filter wrench (65–75mm cap type) (specialty)
• Flat trim clip tool
• 10mm socket
• Shop rags

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Engine oil (0W-20 full synthetic) - Qty: 5 quarts
• Oil filter - Qty: 1
• Oil drain plug crush washer - Qty: 1

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📋 Before You Begin

• Park on level ground, set the parking brake, and place wheel chocks behind the rear tires.
• Warm the engine for 2–3 minutes, then shut it off (warm oil drains faster, but don’t work with it very hot).
• Open the hood and remove the oil fill cap (this helps it drain more smoothly).
• If you’ll lift the front, use a floor jack and set the car onto jack stands before going underneath.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Lift and secure the front of the car

• Use wheel chocks behind the rear wheels.
• Use a floor jack (rated 2-ton minimum) to lift the front at the approved front jacking point.
• Set the car onto jack stands (rated 2-ton minimum) and gently shake the car to confirm it’s stable.

Step 2: Remove the lower splash shield (if equipped)

• Slide the drain pan (at least 8-quart) under the engine area.
• Use a 10mm socket and 3/8" drive ratchet to remove any small bolts holding the shield.
• Use a flat trim clip tool to pop out plastic clips (a trim clip tool is a flat pry tool that removes plastic fasteners without breaking them).
• Set the shield and hardware aside in order. Lay bolts/clips in a neat row.

Step 3: Drain the old engine oil

• Position the drain pan (at least 8-quart) directly under the oil drain plug.
• Use a 17mm socket and 3/8" drive ratchet to loosen the drain plug.
• Finish removing the plug by hand, then pull your hand away quickly so the oil drains into the pan.
• Remove the old crush washer from the drain plug (this is a soft metal ring that seals the plug).
• Let it drain until it slows to a drip (usually 5–10 minutes).

Step 4: Reinstall the drain plug with a new crush washer

• Install the new oil drain plug crush washer onto the drain plug.
• Thread the plug in by hand first to avoid cross-threading.
• Use a torque wrench (3/8" drive) with a 17mm socket to tighten the drain plug: Torque to 30 Nm (22 ft-lbs).
• Wipe the area clean with shop rags.

Step 5: Remove the oil filter

• Move the drain pan (at least 8-quart) under the oil filter area (the filter will spill oil).
• Use an oil filter wrench (65–75mm cap type) (specialty) to loosen the filter, then spin it off by hand.
• Make sure the old rubber gasket comes off with the filter (don’t leave it stuck to the engine).
• Wipe the filter sealing surface clean with shop rags.

Step 6: Install the new oil filter

• Put a small dab of new oil on the new filter’s rubber gasket (helps it seal and come off later).
• Spin the new filter on by hand until the gasket touches, then tighten an additional 3/4 turn by hand.
• If your filter wrench and torque wrench (3/8" drive) setup allows torqueing, tighten to Torque to 13 Nm (10 ft-lbs).

Step 7: Reinstall the splash shield

• Reposition the shield.
• Use the flat trim clip tool to align clips, then press clips in by hand.
• Use a 10mm socket and 3/8" drive ratchet to reinstall bolts snugly (do not over-tighten into plastic).

Step 8: Refill with new oil

• Lower the car off the jack stands using the floor jack.
• Insert a funnel into the oil fill opening.
• Pour in 0W-20 full synthetic, starting with about 4.5 quarts.
• Reinstall the oil fill cap.

Step 9: Start, check for leaks, and set the final oil level

• Start the engine and let it idle for 30–60 seconds.
• Shut it off and wait 3–5 minutes for oil to drain back into the pan.
• Check underneath for leaks at the drain plug and oil filter.
• Pull the dipstick, wipe it with shop rags, reinsert, then check level again.
• Add oil in small amounts using the funnel until the level is near the top mark (do not overfill).
• Total capacity is typically about 4.8 quarts (4.6 L) with filter.

Step 10: Reset the oil maintenance reminder

• Turn ignition to ON (engine can be off).
• Use the center screen and commander knob to navigate one of these common paths:
• Home > Applications > Vehicle Status Monitor > Maintenance > Oil Change > Reset
• Home > Settings > Vehicle > Maintenance > Oil Change > Reset

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✅ After Repair

• Recheck the dipstick level after a short 5–10 minute drive and top off if needed.
• Look again for seepage around the drain plug and filter.
• Pour used oil into a sealed container and take it (and the old filter) to an oil recycling drop-off.
• If you smell burning oil after the change, recheck for spills and wipe down with shop rags.

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💰 DIY vs Shop Cost

Shop Cost: $90-$160 (parts + labor)

DIY Cost: $35-$70 (parts only)

You Save: $55-$90 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.7-1.0 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.