What to Do If Your Car A/C or Heater Smells

by Sep 8, 2021car maintenance0 comments

Tips for what to do if your car AC or Heater Smells.

If you find out a nasty smell coming from the vents when you starting your car and cranking the A/C or heater to max, you are not alone. You may wonder is there something wrong with your car. Before you can figure out how to get rid of the odor, it’s important to tell what types of smells and what they could mean for your vehicle.

Car AC or Heater Smells

Why Your Car A/C or Heater Smells?

The source of a strange odor could come from outside or inside. The air conditioning system of your vehicle can either condition air from outside the vehicle, or condition the air that’s in the vehicle by recirculating it through the system. Strange odors can come through your A/C from inside or outside sources, and your car can usually be resolved by removing or driving away from the odor. However, if your car A/C smells like gas, vinegar, mildew, or even like it’s burning, you’d better pay attention to the smell since there may be cause for concern.

What does it smell like and what it means for your vehicle?


If your car A/C smells like gas, the smell of gasoline is usually an indication of a fuel leak.

While your cabin air filter can filter out dust and other harmful materials, it’s not strong enough to able to filter out stronger smells like gas. So, if your vehicle is leaking gas, that likely the smell of gas will get sucked into your cabin through the A/C.

It’s very important to have your fuel system checked out by a mechanic as soon as possible if you smell gas coming from your vents; since a gas leak can be very dangerous. If you smell fuel in your A/C, it’s best to turn off your car immediately. Then to have your fuel system inspected and repaired by a mechanic if necessary.


If your car A/C has a pungent smell like vinegar when you turn on your A/C or heater. The source could be a bit tricky to pinpoint. In rare cases, certain types of mold can cause an odor smell like vinegar. However, there may be other much bigger issues that cause pungent smell in your A/C. Leaking battery acid or ozone emissions may cause a strong sulfur smell that smells like vinegar. You may try to use a vent and duct cleaner to eliminate the vinegar odor issue. If that does not help, it’s better to have a professional inspect your car’s A/C system.


As your vehicle ages, bacterias can grow in the system where moisture typically collects, especially on the A/C’s evaporator. Mold and bacteria thrive in moist and enclosed spaces, particularly your vehicle’s cooling system. A mildew-like smell can get blasted into your cabin through your A/C vents as a result. You may try a vent and duct cleaner, which allows you to spray into your vents to help neutralize the odor. Or purchase anti-bacterial products that can be applied directly to the A/C and into the vent system to kill bacteria. However, this can only work if the mold or mildew problem is mild. For a better solution, it’s better to have a professional inspect your car’s A/C system and make a deep clean if necessary.


If your car’s A/C smells like burning rubber or plastic, that’s an indicator of issues with the A/C compressor, burning wires, or electrical shorts.

If your car A/C smells like burning oil, that may cause by oil leaking issues. Since oil can leak from engines through gaskets, hoses, and even the oil filter over time. It can emit a burning oil odor that can blow in with your A/C when this leaky oil hits your hot engine or other heated elements under the hood. In this case, you should see a technician as soon as possible to locate and repair the leak.

A burning smell from your car’s A/C is never a good sign in general. Each type of burning smell can be caused by a number of issues. It’s hard to diagnose the problem just by the smell, it’s better to have a professional inspect your car in this case.


A strangely sweet scent is the smell of anti-freeze which is a highly toxic substance. A sweet scent in your car’s A/C could indicate an antifreeze leak in your cooling system. Leaking coolant can be detrimental to your vehicle. If you smell something sweet in your car’s A/C, it’s important to have your vehicle checked by a mechanic and repair the leak.

A/C air filters collect dust, dirt, and pollutants; therefore, the buildup of which can cause unpleasant smells from your vents when you use the AC or the heater. To eliminate stinky and weird odors, make sure you clean your car’s A/C filter every few months.

Learn more about the benefits of buying from Carnex. We believe that all clients deserve to know the good and bad of what they’re buying. Because we wanted to know these when we bought cars. That’s why at Carnex.ca, we will proudly display every detail every step of the way. Browse all the best cars, automobile buying tips, auto insurance, young drivers, driving techniques, auto industry trends from Carnex Blog.

Ultimate Guide for buying a Second-hand Tesla in Canada

Are you looking to buy a second-hand Tesla in Canada? Thanks to their svelte appearance, remarkable performance, and eco-friendly technology, Tesla...

An Ultimate Guide Buying Used Auto Parts in Ontario Canada

If you've got a car, it's inevitable that, at some point, certain parts of your car will wear out, then you will need to find used auto parts in...

Keep your gas costs low by switching over to EVs with Bruce Wu and Carnex

Originally Posted On: Keep your gas costs low by switching over to EVs with Bruce Wu and Carnex...

The Long-Term Value of Electric Vehicles: Do EVs Depreciate at a Faster Rate?

Do EVs Depreciate at a Faster Rate? In recent years, the automotive industry has witnessed a monumental shift towards sustainability with the rise...

7 Best Electric Vehicle For Holiday Road Trips

7 Best Electric Vehicle For Holiday Road Trips EV ranges are expanding, and the average range of new EVs is predicted to be 440 kilometers by 2022,...

The Top 7 Used Electric Hatchbacks Available In Canada

The Top 7 Used Electric Hatchbacks Available In Canada Hatchbacks are a type of car with a rear door that opens upward to give access to a large...

The Top 7 Reasons to Buy a Used Electric Vehicles in 2022

By entering 2022, electric vehicles are becoming super popular in Canada as people become more mindful of climate change. Driving an electric...

11 Most Popular EVs In Canada For 2023

11 Most Popular EVs In Canada For 2023 Electric vehicles have become a popular choice for Canadians in recent years. With the number of EV models...

11 ways you can help make Ontario’s roads the safest in North America

Being a responsible driver takes a combination of skill and knowledge, and more importantly, a good driving attitude. In this post, we list 11 tips...

Who is Carnex?

Carnex is an online EV dealer built for Canadians to buy and sell electric vehicles. Our mission is to provide Canadians with an alternative and transparent way to buy and sell used electric vehicles and to accelerate the transition to a sustainable green future.

Carnex.ca is Canada’s first e-commerce platform for used Electric Vehicles. Carnex is the leading Online Car Dealership in Ontario, with the company’s headquarters located in Toronto, Ontario.
Carnex is the fastest and cheapest way to buy a car online. We deliver to your door and collect your old car without extra charges. Buy Now-Pay Later Financing is available.

Why buy from Carnex?

Carnex is trusted by over 18 million buyers to find amazing discounts on used EVs and new EVs in their neighbourhood. Carnex specializes in electric vehicles, and we make the effort to make sure your EV purchase from us will be worry-free. Our skilled EV technicians perform a comprehensive diagnostic on all of our electric vehicles at Carnex because your satisfaction is very important to us. Carnex.ca will help you find the best EV bargains among the listings across Canada, and we’ll provide you with the vehicle history and comprehensive reviews for each EV.

Why Choose Us

We choose to only sale quality and zero-accident used vehicles. We are so confident in our cars that we will shamelessly show you all the perfections and imperfections of the vehicle – from the Chasis pictures to chipped paint spots.

We also offer a 9-day no question asked return policy and an 100-day in house mechanical warranty to make your purchase risk-free.

Get In Touch

14 + 12 =