Air conditioning in your vehicle is no longer a luxury. We’ve got used to it since manufacturers no longer sell AC as a luxury additive. You will find it in virtually any base model vehicle that passed a safety inspection.
While the AC in your brand new vehicle won’t have an annoying smell, chances are things will start developing a ‘character’ as the years and miles pile up.
As time goes by, the characteristic smell could turn from something you barely notice to an annoying stench that you can’t bear. In most cases, the stench will be strongest when you first turn on the AC and could reduce or even dissipate as the system keeps running.
Regardless of when you get a smell, there are different types with each hinting at a different problem.
A Musty and Moldy Smell
This is a common problem in the wet season. If there’s more moisture in the air, more of it will be trapped in the air intake vent, the evaporator, evaporator case, condenser, and other parts of the vehicle’s AC system.
The trapped water creates dampness that is the perfect breeding ground for mold and mildew. Sometimes, even other small forms of algae can grow especially if the car has been abandoned for long.
Moreover, the problem will be more profound if the AC evaporator case drain plug is clogged. Most vehicles have a drain hole somewhere in the middle of the car’s underside. That is why you will occasionally see a harmless pool of clear water under the car after using the AC for a while or after leaving your vehicle out in the rain.
Deal With the Pooling Water
The main cause of moldy wet smells is accumulating water and rising dampness. This will only happen if your AC system isn’t draining properly.
Start by snaking the drainage hole with a slender but stiff wire to pull out any gunk clogging the drain. A wire coat hanger could do the trick or some old binding wire with a small 90 degrees bend at the end will do the trick.
Be careful not to push too far and damage something. Most drain hoses are more than 10 inches long. If you don’t get any gunk out or encounter tough resistance too soon, get a mechanic or some wrenches and time to remove and manually unclog the hose.
ProTip: If your drain hose is really blocked, all that water from the condenser will seep into the passenger compartment making the carpets wet. Inspect your carpets for this tell-tale sign
After clearing the drain hole and fixing any other water pools at the intake vent under the hood, replace the filters and let your AC run on fan mode only for a while on a hot day to dry everything out.
You can go a step further and clean your AC ducts and vents. IT is time involving and needs some ingenuity if you DIY but you can pay a detailer to get it done professionally.
Stuffy Stale Air
Over time, your cabin filter gets dirty and worn out rendering it inefficient. It won’t get rid of any dirt in the intake air or within the vents and will let it blow straight to your nose. It will also be releasing small amounts of the dirt it has trapped over the years.
Changing your cabin filter is simple. Check your user manual for the location and changing guidelines.
Don’t wait until your AC smells stuffy before changing the filter. Experts recommend changing it at least once a year.
A Chemical Like Smell
The AC evaporator has a refrigerant that does all the heavy lifting and ensures the blower sends the right temperature air through your vents.
If the evaporator is punctured or leaking, it will leak and the air stream will capture some of that refrigerant and oil sending it into the cabin. You will register this smell as an alien chemical smell.
Get a professional vehicle air conditioning system mechanic to look into the problem and help you fix it. DIYing AC compressor problems isn’t a good idea.
A Sweet but Pungent Smell
Finally, your AC system has a heater core that gets heat from the engine through the regular engine coolant. IF the heater core is leaky, you will get that sweet pungent odor of coolant in the cabin.
If the leak is bad, you might see a pool of coolant around where the heater core is located within the cabin.
A Generally Dirty Car
If your vehicle is generally dirty, chances are the AC will pick up on the dirt and grime – especially when the AC is in recirculation mode.
Cleaning your vehicle will go a long way in making it smell fresh again. A professional detailing could be the simplest way to get rid of your problems.
Also, ensure the space under your hood where the AC intake vents sit is clean and free of any leaves or moss. In most vehicles, the vents are next to the bases of your windshield wipers. They have small mesh prefilters to keep most of the big pieces of gunk out. Cleaning and clearing them will improve the quality of the air you get every time you turn on your AC.
How Often Should I Service My AC System
Apart from replacing your filter, you should also schedule frequent checks for your AC system to ensure that it stays in optimal working condition.
Pay more attention to it especially if you drive a high mileage vehicle or buy a second-hand vehicle from regions with extreme heat or cold where chances are the users kept the AC on full blast for hours on end.