🔧 Altima - Engine Air Filter Replacement

You’ll be replacing the engine air filter inside the black plastic air box on the left side of the engine bay. This helps your engine breathe clean air and can improve performance and fuel economy.

Difficulty Level: Beginner | Estimated Time: 15-30 minutes

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⚠️ Safety & Precautions

• ⚠️ Park the Altima on level ground, shift to Park, and set the parking brake.
• ⚠️ Turn the engine off and remove the key (or switch ignition OFF) before opening the hood.
• ⚠️ Let the engine bay cool for at least 10 minutes to avoid hot parts.
• ⚠️ Do not unplug any sensors or wiring on the air intake; especially the mass air flow (MAF) sensor.
• ⚠️ Keep dirt and small objects out of the open air box; they can damage the engine.
• ⚠️ Battery disconnect is not required for this job.

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🔧 Required Tools

You'll need the following tools for this repair:

• 🛠️ 10mm socket
• 🛠️ 1/4" drive ratchet
• 🛠️ 3" extension
• 🛠️ Flathead screwdriver (medium)
• 🛠️ Work light or flashlight
• 🛠️ Mechanic gloves
• 🛠️ Safety glasses
• 🛠️ Clean rag or microfiber towel

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• 🔩 Engine air filter (for 2.5L Altima) - Qty: 1
• 🔩 Dielectric grease (small tube, optional) - Qty: 1
• 🔩 Mass air flow sensor cleaner (optional) - Qty: 1

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📋 Before You Begin

• 🚗 Park the Altima on a flat surface, shift to Park, and set the parking brake.
• 🔑 Turn ignition OFF and open the hood using the interior hood release, then lift the hood and set the hood prop rod in place.
• 📦 Locate the engine air filter housing: it’s the black plastic box on the driver’s side of the engine bay, connected to the big intake hose.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Access the air filter housing

• Use your work light to clearly see the top of the air filter box.
• On your Altima, the upper half of the air box is held by metal clips at the front and may have one or two 10mm bolts at the corners.
• Take a moment to look at how the box fits together.

Step 2: Release the air box clips and bolts

• Use your hands to flip open the metal clips along the front edge of the air box lid. They pull away from the lid and down.
• If there are bolts on the air box lid, use a 10mm socket with a 1/4" ratchet and 3" extension to remove them.
• Set the bolts aside in a safe place so they don’t fall into the engine bay.
• Torque when reinstalling: 5-7 Nm (44-62 in-lbs)

Step 3: Loosen the intake hose clamp (if needed)

• Some Altimas allow the lid to lift without removing the intake hose. If the lid doesn’t move enough, you’ll need to loosen the clamp.
• Use a flathead screwdriver (medium) to loosen the metal clamp screw where the big rubber intake hose meets the air box lid.
• Turn the screw counterclockwise 3–4 turns—just enough for the hose to wiggle free, not remove the clamp.
• Do not pull any electrical connectors off the intake tube.

Step 4: Lift the air box lid

• Gently lift the front of the air box lid upward with your hands.
• The back edge of the lid has tabs that sit in slots; tilt the lid up and slightly forward to free those tabs.
• If the intake hose is still attached, carefully rotate the lid enough to expose the filter without straining the hose.

Step 5: Remove the old air filter

• With the lid lifted, you’ll see the rectangular air filter sitting in the lower half of the box.
• Use your hands to lift the filter straight up and out. Note which side has the rubber seal and which way it faces.
• Check the bottom of the air box for leaves, dust, or debris.

Step 6: Clean the air box (no water)

• Use a clean rag or microfiber towel to wipe out any loose dust and debris from the inside of the lower air box.
• Do not use water inside the air box; moisture can damage the new filter and engine.
• If you have MAF cleaner and want to clean the sensor, follow the directions on the can carefully, but do not spray any other sensors or parts.
• Only use actual MAF cleaner, never brake cleaner.

Step 7: Install the new air filter

• Take the new engine air filter out of its packaging.
• Make sure the rubber sealing edge matches the old filter’s orientation.
• Place the new filter into the lower air box with the rubber seal facing up and the filter sitting flat all the way around.
• Run a finger around the edge to confirm it’s fully seated and not twisted.

Step 8: Refit the air box lid

• Position the back tabs of the lid into their slots on the lower air box using your hands.
• Rotate the lid down over the new filter, making sure it sits evenly and doesn’t pinch the filter.
• If you loosened the intake hose, slide the hose fully back onto the air box lid while it’s in place.

Step 9: Secure the lid and tighten the hose clamp

• Use your hands to re-latch all the metal clips along the front edge of the air box. Make sure each one snaps firmly into place.
• If your lid has bolts, reinstall them by hand first, then tighten them using the 10mm socket, ratchet, and extension.
• Torque bolts to: 5-7 Nm (44-62 in-lbs) using the 10mm socket if you have a small torque wrench; otherwise snug them gently—do not overtighten.
• If you loosened the intake hose clamp, use the flathead screwdriver (medium) to tighten the clamp snugly so the hose cannot twist or pull off.

Step 10: Final checks

• Visually inspect the air box lid: it should be fully seated, with no gaps around the edges.
• Make sure all clips are latched and any bolts are tightened.
• Check that the intake hose is fully on and the clamp is tight.
• Remove your work light, close the hood, and ensure it latches properly.

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✅ After Repair

• 🔑 Start the engine and let it idle for 30–60 seconds. Listen for any unusual hissing or whistling around the air box (this could mean an air leak).
• 🚦Gently rev the engine once or twice. It should respond smoothly with no check engine light.
• 📅 Make a note of the date and mileage so you know when you last changed the filter.
• 🧼 If you disconnected or bumped anything, double-check all wiring connectors near the air box are fully seated.

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💰 DIY vs Shop Cost

Shop Cost: $60-$100 (parts + labor)

DIY Cost: $15-$35 (parts only)

You Save: $25-$85 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.3-0.5 hours.

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🎯 Ready to get started?

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