🔧 GLC300 - Engine Air Filter Replacement

Your A4-cylinder turbo needs clean air to run smoothly and protect the turbo and engine. Replacing the engine air filter restores airflow, helps fuel economy, and prevents dirt from damaging the intake system.

Difficulty Level: Beginner | Estimated Time: 0.3-0.6 hours

---

⚠️ Safety & Precautions

• ⚠️ Let the engine cool before working near the turbo and intake piping.
• ⚠️ Keep tools and screws out of the air intake opening (nothing should fall inside).
• ⚠️ Do not pull on wires or sensor housings; move them gently if needed.
• ⚠️ Battery disconnect is not required for this job.

---

🔧 Required Tools

You'll need the following tools for this repair:

• Torx T25 screwdriver
• 8mm socket
• 1/4" drive ratchet
• 1/4" drive extension (3")
• Trim clip tool
• Shop towel
• Nitrile gloves
• Safety glasses
• Flashlight

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Engine air filter - Qty: 1

---

📋 Before You Begin

• Park on level ground, shift to Park, and set the parking brake.
• Open the hood and remove any loose items (rags, tools) from the engine bay.
• Have a shop towel ready to cover the intake opening if you need to pause.
• Take a quick photo before disassembly.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Locate the air filter housing

• Use a flashlight to find the black plastic air box at the front/side of the engine bay (it’s the box connected to the large intake tube).
• Wipe loose dust around the housing with a shop towel so dirt doesn’t fall inside.

Step 2: Loosen the intake tube clamp (if equipped)

• Use an 8mm socket with a 1/4" drive ratchet to loosen the worm-gear clamp where the intake tube meets the air box lid.
• A worm-gear clamp is the metal band clamp with a small screw you tighten/loosen.
• Only loosen enough so the tube can slide off the air box lid.

Step 3: Release any clips or fasteners on the air box lid

• Use a Torx T25 screwdriver to remove (or loosen) the screws holding the air box lid.
• If your lid uses push-clips instead, use a trim clip tool to gently pop them free without breaking them.
• Place screws/clips somewhere safe so they don’t get lost.

Step 4: Open the air box and remove the old filter

• Lift the lid slightly (or swing it open) by hand.
• Pull the old air filter straight out.
• Use a shop towel to wipe the inside of the air box. Do not push debris deeper into the intake path.

Step 5: Install the new air filter

• Insert the new filter into the lower air box.
• Make sure it sits flat and fully seated all the way around (no corners folded).
• If it won’t sit flat, it’s not aligned yet.

Step 6: Refit the air box lid and tighten fasteners

• Lower the lid back into place by hand, checking that the lid meets the housing evenly.
• Use a Torx T25 screwdriver to tighten the air box lid screws.
• Torque to 4 Nm (3 ft-lbs)

Step 7: Reconnect the intake tube and tighten the clamp

• Push the intake tube back onto the air box outlet until it fully seats.
• Use an 8mm socket with a 1/4" drive ratchet to tighten the clamp.
• Torque to 4 Nm (3 ft-lbs)

---

✅ After Repair

• Start the engine and let it idle for 30 seconds.
• Listen for whistling or hissing (this can mean the intake tube isn’t fully seated).
• Check the air box lid seam all around to confirm it’s closed evenly.
• Take a short test drive and confirm there’s no warning light and throttle feels normal.

---

💰 DIY vs Shop Cost

Shop Cost: $80-$180 (parts + labor)

DIY Cost: $20-$60 (parts only)

You Save: $60-$120 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.3-0.6 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.