AudiWorld Forums

Audi: Why Does My Car Interior Smell?

Do you have an odd smell looming inside your Audi? This article explores the various things that could be causing that unpleasant scent.

By Brett Foote - March 29, 2016

This article applies to the Audi A6 C5/C6, A3, A4 B7/B8, Q5/Q7.

Unpleasant smells coming from air conditioning vents or other interior components are nothing new in any car. They might pop up only at certain times of the day or during particular seasons, or you might even smell something funny all the time. Some scents might only occur when the vehicle is warming up, while others might just pop up when it's humid or rainy outside. While most people may try to ignore it, why not track down the problem causing the smell and fix it? Here's how to get the inside of your Audi smelling pleasant again.

Materials Needed

  • New cabin air filter (optional)
  • Flat and Phillips head screwdrivers
  • Air conditioner antibacterial spray cleaner

Step 1 – Check the cabin air filter

A dirty or musty cabin air filter can cause the inside of your car to smell.

Perhaps the simplest (and cheapest) thing to check when you have a funny smell inside your Audi is the cabin air filter. A dirty or wet/musty filter can cause the inside of your ride to smell a bit, especially if you haven't changed it in a while. Which, admittedly, a lot of folks forget to do. So before you drop some cash on cleaning out your system, go ahead and drop a clean cabin air filter in there first.

Figure 1. A dirty cabin air filter can cause the inside of your car to smell.

If your filter is clean or a new one doesn't solve the problem, move on to Step 2.

Step 2 – Cleaning/flushing the air conditioning system

Condensation in the system can lead to bacteria and mildew.

Audi recommends having your air conditioning system flushed every two years, and it's something that virtually no one does on their own. When you don't use your air conditioning over a period of time (like the winter), condensation just sits in the system and eventually mildew and bacteria can grow. Not only that, but clogs can form in the system, especially in pollen season. A dealer can charge you upwards of $80 for a flush, but you can pick up the necessary cleaner at an auto parts store for around $10-$15.

Figure 2. Running some cleaner through the HVAC intake can eliminate bacteria and resulting smells.

If your system still smells after a good flush, move on to Step 3.

Step 3 – Check for clogs in the system

A clogged-up drain can cause a smell.

Over time, dirt and other pollutants can gather in the air conditioner's drain pipe, leading to stagnant water and bacteria growth. Check your drain pipe for clogs and even things like dead animals. Small mice have been known to climb up in the condensation chamber and perish, leading to (as you can imagine) a foul odor.

Figure 3. Check your air conditioner's drainage pipe and clean out any clogs.

Related Discussions