If the inside of your car smells it’s irritating when you cannot get rid of it, let alone figure out where it is coming from. The vents in your car, the seats, and even the exterior of the car can cause the car smells to show up. Cleaning does not always remove the car smells but knowing what is causing it can go a long way towards determining exactly how you would remove the car smells.
1 - Smells like Chemicals
This is a misnomer as you may not even identify it as a chemical smell at this point. If you have opened an old refrigerator in your lifetime that is the smell considered to be "chemical". It smells like a combination of old plastic, rotting food, baking soda, and rubber. It really is a disturbing and distinctive scent that can be smelled from either the inside or outside of the vehicle.
Inspect your inside windows as well as the inside of the windshield. You will be looking for an oily film over the glass. If you find this in conjunction with the smell then the problem is with your cooling and heating system. This happens when the heating core inside the car is leaking coolant. To stop the smell you likely need to have the heating core replaced.
2 - Acidic Smell
If you are detecting car smells along the lines of a weak form of bleach, then you are experiencing a slight acidic smell. This smell will usually appear when the car has been running and hot. Sometimes the smell may appear to come from the tailpipe. This car smell is attributed to a coolant leak that has found its way into the tailpipe. The heat from the car running transfers to the metal of the tailpipe which, in turn, heats the coolant. The coolant gets there through the combustion chamber. Check the levels of your coolant and have a mechanic look for leaks. There is a possibility of fire in this situation.
3 - Decay
Squirrels, mice and other small animals may hide out under your car or in small recesses during extreme weather. There is a risk that this animal could die and decay inside your car. You will notice a very pungent smell of death whenever the car gets hot or when you run the air vents. Have your undercarriage cleaned and spray a solution of two cups of water mixed with 1/2 cup of vinegar into the vents.
4 - Dust
As you drive you attract dust which can wind up inside the vents. An accumulation of dust can cause an odor that smells like musty dirt. Vacuum the vents and treat the interior with water and vinegar.
5 - Mold and Mildew
If you are smelling a musty smell then you may have mold. If the vents are used little and moisture is allowed to accumulate mold can easily form. To clean this use the same technique used to remove animal smells.