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7 Causes of Cars Suddenly Smell Like Poop With Their Solutions!

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Car Suddenly Smells Like Poop

A car suddenly smells like poop is nothing usual. This will create a miserable condition for you.

So, why does a car suddenly smell like poop? The car may smell like poop because of the dirty cabin air. Or you may find stool or animal in the air box, which conveys air to the interior. Rainwater or a dirty carpet can also create this situation. If leakage of diapers or dead animal smell is circulated by the AC air, the car will smell like poop.

That’s not the end. Here other problems are also given with their solution. Stay with us to know more!

Car Suddenly Smells Like Poop

Car Suddenly Smells Like Poop

The cars can smell various things like oily, gasoline, musty, or poop. This will not give you comfort while driving. At that point, you need fresh air and get rid of it. Here are seven possible problems with their solutions are given:

Car Suddenly Smells Like Poop

Problem 1: Dirty Cabin Air Filter

The cabin air filter allows air from the outside and removes the heavy air from the inside. But during this process, a bad odor can come inside the car. That is because the cabin air filter is dirty.

It not only exchanges the air but also removes dust and other harmful elements in the air. Sometimes, shit from rodents, chipmunks, cats, or rabbits may enter the filter and get stuck. While you keep the cabin air filter button on, the smell of poop comes instead of fresh air.

Dirty Cabin Air Filter


You may service your car twice a week. While servicing, the air filter is also cleaned. But it is best to clean it once a month. You can easily clean it by yourself by following the steps below. The cabin air filter is located behind the glove box.

  • Step 1. Open the glove box and remove all the accessories it holds
  • Step 2. Two rubber taps are holding the glove box inside. Press it on one side and free the other side. The glove box will come out easily
  • Step 3. Behind it, you will see a long panel. Pull a clip on each side to remove the panel
  • Step 4. You have reached the cabin air filter. Now pull it
  • Step 5. Take a toothbrush and brush the filter properly
  • Step 6. Spray some bleach on it
  • Step 7. Then take it in a dish full of soap and water and wash it
  • Step 8. Change the soap water and spray bleach again
  • Step 9. Repeat this process three to four times
  • Step 10. Then clean it with fresh water
  • Step 11. Let it dry for a while
  • Step 12. Then place it again

Problem 2: Stool of Animal or Dead Animal Stuck in AC Box

If a mouse or other little animal is stuck or defecates in the AC box while cooling the car, a bad smell, like poop, will come through the HVAC system.

Common problems of the HVAC system in a car are often solved while maintenance is regularly done. But if maintenance is not done for a long time, the smell will become stronger.


Follow the steps below to clean the AC box. 

  • Step 1. First, release the hood
  • Step 2. Pop the clips loose and open the engine air filter
  • Step 3. Pull up and find a way to separate them
  • Step 4. Remove the filter. You will be able to see animals like chipmunks or rats with their nest inside them
  • Step 5. Remove the air intake duct and check it properly
  • Step 6. Now unscrew the AC box and remove the animal and nest
  • Step 7. Clean it with water
  • Step 8. Place it back and fix all the parts

Problem 3: Dirty Carpet or Floormate

The carpet or floormate may not get washed for a long time. It can cause a bad odor inside the car. This can happen if you accidentally drop food on the carpet and leave it for many days.


Dirty Carpet or Floormate

Try to clean the floormate immediately after dropping any food or juice. Regular cleaning of the carpet is a good habit of staying clean and free from bad odor.

Problem 4: Rotten Food or Animal in Trunk, Interior, or Engine Compartment

Sometimes leftover wet foods are kept in the car for a long time. Or there may be a dead rodent or squirrel stuck in the engine or trunk compartment. After 5-6 days, these elements start spreading a shit-like smell. Whenever you enter the car, you can feel the presence of a strong smell.


To get rid of the smell-

  • Step 1. Find out the source of the bad odor
  • Step 2. Wear gloves
  • Step 3. Carefully throw the rotten food or animal into the dustbin
  • Step 4. Clean with bleaching powder and properly disinfect the place
  • Step 5. Let the windows and doors open for 15-20 minutes
  • Step 6. Use an air freshener

You should lock the window, doors, or engine compartment before you leave your car.

Problem 5: Entering Water into the Interior

A negligent but common cause of a poop-like smell in your car is entering the water. It occurs mainly in rainwater. The evaporate case then collocates a lot of moisture when rainwater enters. That helps in the growth of fungus. 

This process is not only creating a bad smell but also creating health hazards, mainly for your lungs.

Entering Water into the Interior


You should seal the leakage to stop entering the water. Then you should clean the molds. Finally, fix or replace the evaporator case. It is important to do. Otherwise, other problems related to evaporator leakage will suffer a lot.

Problem 6: Remain Close for A Long Time

Your car may not be used for a long time or remain closed; then you may find a poop-like odor. Rats usually take this advantage and take the car as their residence.

It will gather a lot of food and unwanted waste products. Besides, it will defecate into the car. All the things mixed with a closed place odor smell like poop.


Do not let your car unused for a long time. Timely give it service care. Otherwise, there will be a lot of problems in the car for being unused for a long time.

Problem 7: Diaper Leakage

A silly but possible cause that your car is poop-smelling is the diaper leakage of your baby. A little smell can make the environment change. Or maybe you have forgotten to remove the diaper from the car. It also can create the same situation.


Immediately turn off the AC and open the window. Throw the diaper and clean the baby as soon as possible.

These all are the possible causes why your car is smelling so bad. Check the causes in your car. If you still can not fix it, call an expert.

Car Interior
If you’ve noticed an unpleasant smell in your car, such as a smell similar to poop, it’s essential to investigate and address the issue promptly. While the odor could be attributed to various causes, it’s important to rule out any coolant leaks as a potential source. Coolant leaks can result in odors and require immediate attention to prevent engine damage and overheating. Our article on how to identify and address coolant leaks in your car provides valuable insights into detecting and resolving coolant leaks effectively. By understanding the signs of coolant leaks and taking appropriate measures, you can maintain the proper functioning of your vehicle’s cooling system. Furthermore, understanding the role of coolant in preventing engine overheating is crucial. Coolant plays a vital role in regulating the engine’s temperature and preventing overheating. To learn more about how coolant helps in preventing overheating, you can refer to our article on does coolant prevent overheating? This article provides in-depth information on the importance of coolant and its function in maintaining the optimal temperature of the engine. By ensuring proper coolant levels and addressing any leaks or issues, you can safeguard your vehicle from potential overheating problems.


These are some frequently asked questions by people about car smells.

Q: Why does car ac smell like dog poop?

Cars smell like dog poop because any animal has died or built a nest in the system or of a lot of fungi in the car or of the evaporator leakage. Another possible cause is that dog poop has transferred into the car through your shoes or any dog entered the car and defecated.

Q: Why does windshield wiper fluid smell like poop?

Windshield wiper fluid smells like poop because water enters into the reservoir or bacteria or fungal growth occurs. Here in all these two conditions, chemical reactions have taken place and changed the fluid elements. So, smelling like poop can cause a chemical reaction.


Car smells like poop can happen when you are careless with your car or not giving regular maintenance for a long time. The dirty carpet can make this smell if food is rotten or your shoes’ dirt stays on it.

Accordingly, if the stool or dead animals are stuck on the AC box and air filter, it will smell like poop. And for many other reasons discussed above. Hope you get solution to your car’s poop like smell. Take steps given above to get rid of this smell. Thanks for reading.

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