Disclaimer: As an Amazon Associate I earn from qualifying purchases. It may also contain other affiliate links. Read our affiliate disclosure.

car ac smell like pee

Why Does My Car AC Smell Like Pee & How To Get Rid Of It?

Car air conditioners are essential for car owners, especially on hot days. It may begin to smell like urine over time, making you wonder what is wrong with your car AC.

If your car’s air conditioner smells like pee and you’re not sure what to do about it, you’ve come to the right place. In this post, I will discuss the most common causes of this problem as well as how to remove and prevent it.

Simply put, mold and bacteria can cause a pee-like odor in your car’s air conditioning system. The smell will go away once these microbes are cleaned.

Continue reading to find a wealth of useful information on this subject.

Why does my car AC smell like pee?

While your car’s air conditioner smells like pee, this does not imply that someone has tricked you and peed on it. This urine odor is caused by other factors.

Mold and bacteria grow in the AC system

A car air conditioner, like other types of air conditioners, uses an evaporator coil to cool and dehumidify the air. The moisture that has been removed will either accumulate and drain through a drain hole or dissipate.

If the drain hole becomes clogged or the evaporator does not have time to dry before shutting down, moisture will remain in the system, encouraging mold and bacteria growth.

Mold and bacteria can both smell like pee. This is due to the fact that some mold species can produce Ammonium, which is also present in urine. Protein is a food source for some bacteria. The breakdown of some proteins produces a pee-like odor.

Mold and bacteria, rather than actual urine, are the main causes of odor in car air conditioners.

Filthy cabin air filter 

dirty cabin air filter

The urine odor in your air conditioner is not always caused by the air conditioning system. When the cabin air filter, which controls air quality, becomes dirty, it can emit a foul odor.

Because the filter can become clogged by dust, dirt, and dead skin cells, it can become a breeding ground for mold and bacteria, causing a pee smell and allowing the strange odor to circulate throughout the cabin.

Small animal

In rare cases, small animals such as mice can get into the intake system and relieve themselves there. Their urine and feces can emit a foul odor.

Furthermore, they may perish within the system. Strange odors can also be produced by decomposing carcasses.

Dangers of urine smell in a car AC

Some people detect a pee-like odor in their car air conditioner and leave it unattended. It’s not a good plan.

This is because the odor indicates the presence of mold and bacteria, which can cause a variety of respiratory issues such as allergic reactions, shortness of breath, and lung infections.

Mold spores and bacteria can also travel to every corner and surface of your vehicle in search of a home. That is, the smell will become much more difficult to remove over time.

Finally, those who intend to sell their vehicles should address this issue because no one wants to buy a vehicle with an unpleasant odor.

How to remove urine smell in a car AC?

Since getting rid of the pee-like smell is essential, let’s talk about how to get the smell out of your car air conditioner.

Unclog the drain hole

We need to unclog the drain hole first because it could be the source of the moisture in your AC.

Turn on your car and turn on the air conditioning for a few minutes to see if there is any water dripping on the ground. Otherwise, the drain hole is most likely clogged.

As long as you have some basic knowledge, you can detach and clean the drain line yourself.

Clean the mold and bacteria 

To get rid of these microbes, you need the help of chemicals. There are two ways to do that.

1. Use Lysol

Keep your vehicle and ac system running, and ensure the fan is at its highest. As Lysol fumes harm humans, the windows should be open.

The intake vents are located at the bottom of the windshields. Take a can of Lysol and spray it into the intake vents. Wait for 10 minutes and then test if the smell of pee has gone.

2. Use an HVAC system cleaner

If the Lysol does not work as expected, you should use a stronger cleaner. The HVAC system cleaner can usually handle the job.

Instead of using the intake vents, apply the cleaner directly to the AC unit.

Remove the drain tube cap and apply the cleaner to the AC. Allow the cleaner to sit for about 15 minutes before allowing it to drain.

Replace the filthy cabin air filter

Again, the cabin air filter can attract the odor of pee. You must replace it on a regular basis. Fortunately, replacing it is simple, and you can easily find a replacement online.

See a Mechanic

If none of the methods works or you don’t have the time, you should consult a mechanic, who can solve the problem for help. 

How to prevent the pee-like smell in a car AC?

The last thing you want to see is the pee-like small in your car AC returning after a while. Don’t worry too much! There are some things you can do to avoid it.

Turn off the car AC and use the fan before stopping driving

If you turn off your car’s air conditioning system just before you stop driving, moisture will remain in the evaporator, promoting mold and bacteria growth.

You can avoid it by turning off the air conditioner five minutes before and turning on the highest fan setting. This will allow enough time for the AC to dry.

Regular maintenance 

Having your vehicle serviced on a regular basis, including the ac system, can help keep your vehicle in top condition. You can detect the blockage in time to avoid the pee-like odor and replace the air filter to improve the air quality in your vehicle.


When you find your car AC starts to emit a urine smell, you should take some action. 

The causes of the pee-like smell in the car AC often boil down to the growth of mold and bacteria. To repair it, check if the drain tube is clogged, and clean the AC system with Lysol or other cleaners.

To avoid this issue, turn off the air conditioning and run the fan before pulling over.

If your air conditioner at home also suffers from a urine smell, check here to know more details. 

Avatar photo

Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested more than 150 products in person, including humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.

Leave a Comment

Table Of Content