How to Replace the Engine Air Filter on a 2018 Mazda 3 (DIY Guide)
Step-by-step instructions with tools, parts list, safety tips, and post-installation checks for 2012, 2013, 2014, 2015, 2016, 2017, 2018
How to Replace the Engine Air Filter on a 2018 Mazda 3 (DIY Guide)
Step-by-step instructions with tools, parts list, safety tips, and post-installation checks for 2012, 2013, 2014, 2015, 2016, 2017, 2018
🔧 3 - Engine Air Filter Replacement
Replacing your A3’s engine air filter keeps dirt out of the engine and helps it breathe properly. It’s a quick job that usually requires no special tools, and it’s a great first DIY service.
Difficulty Level: Beginner | Estimated Time: 10-20 minutes
⚠️ Safety & Precautions
- ⚠️ Work with the engine off and cool to avoid burns.
- ⚠️ Keep fingers clear of the cooling fan area; it can run unexpectedly on some cars.
- ⚠️ Don’t drop anything into the air box or intake tube.
🔧 Required Tools
You'll need the following tools for this repair:
- Nitrile gloves
- Safety glasses
- Flashlight
- Shop towel
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Engine air filter - Qty: 1
📋 Before You Begin
- Park your 3 on level ground and shift to Park.
- Turn the ignition off and let the engine cool for 10-15 minutes if it was running.
- Open the hood and locate the air filter box (black plastic box connected to the intake tube).
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Locate the air filter housing
- Use a flashlight to find the air filter box near the engine, attached to a large plastic intake tube.
- Wipe loose dirt off the top with a shop towel so debris doesn’t fall inside when opened.
Step 2: Open the air filter box
- Put on nitrile gloves and safety glasses.
- Release the metal retaining clips around the air box by hand.
- If your air box uses clips: flip them open and gently lift the lid.
- Don’t force it; check for a missed clip.
Step 3: Remove the old filter
- Lift the air box lid enough to access the filter (you usually don’t need to fully remove the lid).
- Pull the old filter straight out by hand and note its orientation (which side faces up).
- Use a shop towel to wipe out any loose dirt in the bottom of the air box.
Step 4: Install the new filter
- Place the new engine air filter into the air box in the same direction as the old one.
- Make sure the filter sits flat and the rubber edge (gasket) seals all the way around.
- A pinched edge can cause unfiltered air.
Step 5: Close and secure the air box
- Lower the lid back into place, making sure it aligns evenly with the bottom half.
- Snap all retaining clips closed by hand.
- Do a quick visual check that the intake tube is still seated and nothing is trapped between the lid halves.
✅ After Repair
- Start the engine and let it idle for 10-20 seconds; listen for any whistling or hissing (can indicate the air box isn’t sealed).
- Recheck that all clips are fully latched and the air box lid sits evenly.
- Write the mileage/date on the filter box with a marker (optional).
💰 DIY vs Shop Cost
Shop Cost: $60-$120 (parts + labor)
DIY Cost: $15-$35 (parts only)
You Save: $45-$85 by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.2-0.4 hours.
🎯 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.

















