What is causing that bad smell in your car?

Eliminate bad smells by leaving the windows open to air out your car.  PHOTO/David Lubowa

What you need to know:

When your car smells a little off, it is trying to tell you something. Paying close attention to the way your car smells can help you track down the culprit and fix it.

If your vehicle is giving off an unusual or sickening odour instead of that instantly identifiable new-car smell, follow your nose and find the source of the aroma. Bad smells can lead to expensive repairs or health hazards and should not be ignored. Here are some of the top reasons your car might smell and what you need to do about it:

Car lubricants

Apart from liquids that pour in your car, some car interior odours are caused technically by car lubricants. Ronnie William Kyazze, a mechanic, says inorganic fluids and lubricants such as brake fluid, automatic and manual transmission fluid and engine oil  also cause your car interior to smell. 

“Brake fluid and transmission fluids are corrosive with all materials, including metals. If you transported such liquids and were not tightly covered and accidentally poured in the car, it will produce a pungent smell that takes time to clear even after washing the car,” Kyazze explains.

Short circuits

If underlying car wires burn due to electrical short circuits, you will get a smell of burnt plastic. In this case, stop and have it fixed immediately because it could cause more damage. Like car lubricants, the smell is also temporary and clears over time. 

Poor aeration

If a car is closed for a long time, depending on the mechanical state it was in before parking, it may develop a stuffy smell, which Kyazze says also takes time to clear. The solution is to have it opened as you drive to allow aeration. 

While the air conditioning system may also transmit some water and coolant that goes into the cooling system of the car, the heat could come into the car through the AC vents and create a temporary smell.

Other causes of bad car smells could be from mechanics who sit with dirty overalls, sweat and lubricants in your car during service. Kyazze advises that your mechanic should be vigilant about their personal hygiene before accessing your car. 

Wet carpets

Eric Lwanga, a car interior cleaning expert, says most car carpets are coated with a woolen or cloth material on the surface. When washed, these carpets need approximately half a day to dry if they have been wholly immersed in water or sprayed with a jet spray.

“The surface of a car carpet is like a sponge. If you want it to dry well, you must give it time under the sun. The outcome of not giving your carpets time to dry will be bad odour. It is important that after washing the carpets and the car floor where they are placed, the car doors are left open so that the interior also dries well,” Lwanga advises.  He adds that car washing requires using detergents which require a great amount of water and time to rinse out thoroughly to keep the car from smelling. 


Lucky Jesse Kwesiga of Tango-7 Auto Centre in Entebbe, says some dirt that may cause irritating interior car odour in most cases hides under your car seats. When seats are taken out and the car appears like a shell, they (seats) have to be scrubbed thoroughly. When you see a part of your car seat dirty or stained, the dirt may not be on top, but underlying in the internal thick mattress material. When the internal source of dirt is not dealt with, the dirt and smell will always surface. Stains normally come from liquids such as milk or juices that pour in the car. 

“Eliminating such dirt and stain from seats means they will not dry in one day. It requires more days of constant sunshine to dry. If you do not give seats time to dry well, they will develop a smell similar to a dead rat,” Kwesiga explains.


Kwesiga explains that car detailing involves polishing the car body, removing the car seats, carpets, floor carpets and all other material that locks the carpet tightly from their positions. A good job involving the above process takes two to three days, depending on the amount of car detailing you want done, unlike a normal car wash.

“Detailing is under the care aspect because all work under detailing is more of preventive maintenance. When you are driving and the windows are open, the last metal layer beneath the final car carpet becomes wet and smelly after attracting moisture. The metal element rusts and if you do not discover it earlier, your car body that is meant to last more than 20 years will start developing holes underneath. After cleaning off the rust, it has to be re-sprayed to prevent the car from further rusting,” Kwesiga advises, adding that detailing costs between Shs50,000 to Shs100,000 depending on where you have it done.

Unlike Kwesiga, Baguma recommends leather car seat covers as protective measures for your fabric-covered car seats. Seat covers, Baguma says, are easy and fast to clean of any liquid that may pour in the car. 

According to Abubaker Kasozi, a car accessories dealer, a set of leather seat covers costs between Shs300,000 and Shs800,000 depending on the quality and where you buy them from.

Apart from wiping the car seats with a wet cloth and washing car carpets, the alternative could be using a vaccum cleaner to get rid of dirt inside your car. Walter Ojok, a cleaner with one of the cleaning and fumigation companies, says a hoover sucks underlying dust, food droppings, small dead cockroaches and soil from cloth-coated and complex surfaces such as car seats and interior car floors that may be hard to see with your eyes.


It is normal to smell a little gasoline when a cold engine is first started because of incomplete combustion. If you smell gas fumes after the engine is warm, though, the gas cap could be loose or the evaporative emissions control system, which is supposed to contain fuel vapors and recycle them through the engine, could be leaking or clogged. Even worse, gas could be leaking from the tank or another part of the fuel system, such as the fuel line. Always investigate gas smells you discover when your car is parked before starting the car and potentially igniting the fuel.