Where to Find the Air Filter on an Audi A4

The main engine air filter on most modern Audi A4 models is located in a rectangular airbox in the engine bay, typically on the right-hand side (passenger side in left-hand-drive cars), while the cabin air filter is usually located behind the glovebox or under the cowl at the base of the windshield. Understanding which filter you’re looking for—and where Audi has placed it on your specific generation—helps you access and replace it safely.

Understanding Which Air Filter You Mean

When drivers ask “Where is the air filter on an Audi A4?”, they usually mean the engine air filter, but the car actually has two common filters often called “air filters”:

The following list explains the two main filters and what they do in the car, so you can identify which one you need to locate.

• Engine air filter: Cleans the air going into the engine for combustion, affects performance, fuel economy, and engine longevity.
• Cabin (pollen) air filter: Cleans the air entering the passenger compartment through the HVAC system, affects air quality and odor inside the car.

Knowing the difference between these two filters is essential because they sit in different locations, require different procedures to access, and are replaced on different schedules.

Below is a generation-by-generation guide for the Audi A4’s engine and cabin air filter locations, covering the mainstream models up to the current B9 generation (as of late 2024).

Engine Air Filter Location by Audi A4 Generation

Audi A4 B5 (1994–2001)

On the first-generation A4 that many enthusiasts still maintain, the engine air filter sits in a fairly traditional spot in the engine bay.

The following list describes where to find the air filter on B5 A4 models and what to look for when opening the hood.

• Position: In a black plastic airbox on one side of the engine bay, usually toward the front corner, near the fender.
• Shape: Rectangular airbox with metal clips or screws holding the lid.
• Access: Open the hood, locate the large intake duct leading from the grille area to the airbox, then undo the clips/screws to lift the lid and reveal the panel-style filter.

Because the layout is relatively simple on the B5, owners can typically spot the airbox quickly as the large, square plastic housing connected to a snorkel pointing toward the front of the car.

Audi A4 B6/B7 (2001–2008)

The B6 and B7 generations share similar platforms and broadly similar under-hood layouts, so the air filter location is almost identical across these model years.

The list below outlines what you will see when you pop the hood of a B6/B7 and how to recognize the airbox.

• Position: On the right-hand side of the engine bay (passenger side in left-hand-drive vehicles), close to the fender.
• Airbox design: Large, rectangular black plastic housing with intake ducting running to the front of the car.
• Access steps (overview):
  

  • Open the hood and locate the mass air flow (MAF) sensor and the intake duct going into the airbox.
  • Disconnect any electrical plug on the MAF if necessary (some replacements can be done without unplugging).
  • Undo the metal clips or Torx screws that hold the lid to the lower half.
  • Lift the lid slightly and slide the filter element out.

On these generations, the air filter housing is fairly accessible, making DIY changes straightforward for most owners with basic tools.

Audi A4 B8 (2008–2016)

The B8 A4, including the facelift (often called B8.5), introduced a more compact engine bay layout, but the air filter location remains intuitive once you know where to look.

The following points describe where the engine air filter sits in the B8/B8.5 A4 and what distinguishes it from surrounding components.

• Position: Typically on the right-hand side of the engine bay (passenger side in left-hand-drive markets).
• Visual clue: A fairly flat, wide plastic airbox with a duct leading from the front grille area or from a snorkel near the radiator support.
• Engine types:
  

  • 2.0 TFSI petrol: Airbox sits to the right of the engine cover, connected by a rubber/silicone intake hose.
  • Diesel variants (TDI): Similar position, though surrounding components (like intercooler piping) may differ slightly.

• Access: Usually requires a Torx or Phillips screwdriver to remove the screws in the lid before lifting it up and pulling the filter panel out.

While the B8 engine bay looks denser than earlier models, the airbox is still one of the largest and easiest-to-identify plastic housings, making it relatively easy to find once the hood is open.

Audi A4 B9 (2016–Present)

The current-generation B9 A4 (including the facelifted versions on sale through 2024) retains a similar philosophy: the engine air filter remains in a rectangular airbox in the engine bay, but styling and plastic covers can make it less obvious to first-time owners.

The following list provides a practical way to locate the air filter on a B9 A4 and notes small differences depending on engine configuration.

• Position: Typically on the front-right corner of the engine bay (passenger side in left-hand-drive markets), near the headlight and radiator support.
• Appearance: Large black plastic box with an intake snorkel leading to the front grille area and a flexible intake hose running from the box to the turbocharger.
• Engine variants:
  

  • 2.0 TFSI / 2.0 TDI: Airbox sits to the right of the main plastic engine cover, often slightly forward.
  • Mild-hybrid versions: Layout is similar, though additional wiring and components may crowd the area.

• Access:
  

  • Open the hood and remove any decorative engine cover if it blocks access.
  • Locate the large rectangular airbox and the Torx screws around the perimeter of the lid.
  • Undo the screws, gently lift the lid, and slide out the rectangular panel filter.

On B9 models, the airbox is integrated cleanly into the under-hood design, but following the intake hose from the turbo or the snorkel from the grille will reliably guide you to the filter housing.

Cabin (Pollen) Air Filter Location by Generation

Confusion often arises because the cabin air filter is not in the engine bay at all. Instead, it’s located where outside air enters the HVAC system or near the glovebox, depending on generation.

B5, B6, B7: Under the Cowl at the Base of the Windshield

On earlier A4s, the cabin filter usually sits under a plastic cover just below the windshield, on the passenger side.

The following list explains how to identify and reach the cabin filter on these earlier generations.

• Position: Under the plastic cowl panel at the base of the windshield, generally on the passenger side.
• Access:
  

  • Open the hood.
  • Locate the long plastic trim piece that runs along the base of the windshield.
  • Remove a small access cover or section (often held by clips or screws) to reveal the rectangular cabin filter housing.
  • Slide the old filter out and insert the new one, following the airflow direction arrows.

Because the cabin filter sits in the plenum chamber, it is exposed to leaves, dust, and moisture, making periodic replacement particularly important in these generations.

B8 and B9: Behind or Below the Glovebox

On later A4 models, Audi moved the cabin filter to a more interior-focused location, usually accessible from the passenger footwell or behind the glovebox.

The following list summarizes the common layout for the B8 and B9 generations and what you’ll encounter when replacing the cabin filter.

• Position:
  

  • Typically behind a small rectangular cover in the passenger footwell area, underneath or behind the glovebox.
  • On some versions, directly behind the glovebox, accessible once a trim panel is removed.

• Access:
  

  • Move the passenger seat back to create working room.
  • Look up under the glovebox for a plastic cover panel; it may be held by Torx screws or clips.
  • Remove the panel, then slide out the cabin filter (usually a long, narrow element).
  • Insert the new filter, again paying attention to airflow arrows.

This interior location helps protect the cabin filter from heavy debris and makes access possible without opening the hood, though it may demand some awkward body positioning in the footwell.

How to Confirm the Air Filter Location on Your Specific A4

Audi has kept air filter locations broadly consistent, but there are variations between engines, drivetrains, and markets. Verifying your exact layout prevents confusion and mistakes.

The following points outline reliable ways to double-check the exact air filter location on your particular Audi A4.

• Consult the owner’s manual: Most Audi A4 manuals include diagrams of the engine bay and identify the engine air filter housing and cabin filter access panel.
• Check engine code and model year: For example, a 2.0 TFSI in a 2013 A4 B8 will have a slightly different layout than a 3.0 TDI or a later B9, even though the airbox concept is the same.
• Look for the intake path: Follow the plastic or rubber intake tube from the turbocharger back to the largest plastic box it connects to—that box almost always contains the engine air filter.
• Use VIN-based diagrams: Online parts catalogs and Audi dealer systems can show exploded views of the air intake and climate systems for your exact VIN.

Confirming with documentation or diagrams ensures that you open the correct housing, avoid damaging clips or sensors, and purchase the correct replacement filter size and type.

Why Knowing the Air Filter Location Matters

Locating the air filter is not just about curiosity: routine filter changes can significantly affect how your Audi A4 feels to drive and how comfortable its cabin is.

The following list highlights the main reasons it is worth learning where both filters live in your car.

• Engine performance and efficiency: A clogged engine air filter can reduce power, increase fuel consumption, and, in extreme cases, stress the turbocharger or mass air flow sensor.
• Cabin comfort and health: A dirty cabin filter can cause musty smells, foggy windows, and reduced airflow from vents, as well as more dust and pollen entering the interior.
• Cost savings: Knowing the location and access method allows many owners to replace these filters themselves, avoiding simple labor charges at workshops.
• Preventing secondary issues: Neglected filters can allow debris into the HVAC system or fine dust into the engine intake, leading to more expensive problems over time.

Being familiar with the air filter locations helps you stay ahead of maintenance, preserve your A4’s driving character, and maintain a cleaner, more pleasant interior environment.

Summary

On an Audi A4, the engine air filter is almost always located in a large rectangular plastic airbox within the engine bay—usually on the right-hand (passenger) side for left-hand-drive cars, near the fender or front corner. The cabin air filter is either under the cowl at the base of the windshield (earlier generations like B5–B7) or behind/under the glovebox in the passenger footwell (B8 and B9). While specific details vary by model year and engine, following the intake ducting under the hood or consulting the owner’s manual will quickly confirm the exact location for your particular A4.

How often should you change the air filter on an Audi A4?

How Often Should I Replace My Audi Air Filter? In general, air filters should be replaced between 15,000 and 45,000 miles.

Where is the cabin air filter on a 2017 Audi A4?

So what you’re going to want to do is pull it down like this. And pull it towards you like that if you can to get it out you can see the filter. Here let me turn the AC.

What is the most common problem with Audi A4?

Top Audi A4 Problems

• Decreased Power and Poor Fuel Economy.
• Clogged Plenum Tray Drain.
• High-Pressure Fuel Pump Failure.
• Excessive Oil Consumption.
• Engine Misfire.
• Suspension Parts Wear Prematurely.
• Flasher Relay and Control Module Failure.
• Engine Failure.

Can I replace my air filter myself?

Yes, most air filters are fairly easy for a driver to replace, so there’s no need to pay a markup for them to spend 30 seconds on the install. and yours look like a simple no tool process.