Apartment Smells Like Car Exhaust – Here’s How to Fix

how to fix smell of car exhaust fumes in the apartment

Exhaust fumes are easily recognizable by their pungent chemical smell, but their stench isn’t the only unpleasant thing about them.

These fumes are also full of carbon monoxide, which is deadly when inhaled.

Any exhaust smell that you might be noticing around the house is one you need to get rid of right away before it becomes a threat as much as it is an unpleasant nuisance.

In order to do so, you’ll first have to find the source of the fumes and fix it up.

Beginning the search can leave you not knowing where to turn, but in this article, we’ll show you how to track down the source of the smell while also offering four different ways to get rid of it.

Causes of Exhaust Fume Smells and How to Fix Them

Before you start to hunt down the leak, beware and prepare for exposure to carbon monoxide.

Regardless of whether you know where it’s coming from or not, you should find out the levels of CO that are present. CO is always found in toxic exhaust fumes, and it can cause you to suffocate.

To start, shut off all of the appliances in the house that burn oil or gas, such as the water heater or furnace.

From there, get a carbon monoxide detector that you can place near the source of the exhaust smell.

Anything that is over 100 PPM on the readout is a dangerous level of carbon monoxide for children and adults alike.

If you have a gas mask on hand, no matter how high or low the readout is, it is recommended that you wear it just to be safe. Then detect the main causes of exhaust fume smells that is lingering around.

1. Faulty Flue Ducts

One of the causes of the smell could be that the air can’t properly escape and is instead filling the home.

When this happens, an easy culprit to pick out is that of a faulty exhaust duct.

There are a few things that could be responsible for a faulty duct, including:

  • A flue duct that is rusted through
  • Parts of a duct could have leaks or have separated

Usually, you can find out if you have these issues with your flue by the fact that you could have cleaned the entire duct right after the exhaust smell showed up, but the smell got even stronger following cleanup.

This will happen only if the flue has an issue such as this, as a cleanup can make the damage worse and bring in more exhaust fumes.

The Fixes

Below are the steps you can take to repair a broken flue duct:

Find the source.

Regardless of whether there are separated parts causing the smell or the flue is covered in rust, you’ll need to be sure which one is the source.

In order to do so, you’ll need both a strong flashlight and a trouble/drop light.

Shut the system off entirely and remove the roof cap. Light up the duct from the bottom using a flashlight as you insert a drop-light into the duct.

Be sure you can see clearly into the duct and look for any damaged, rusty, or otherwise broken parts in the duct. After you’ve located the damage, you can move on to the next step.

Remove the rust.

If you found a rusted flue pipe or just a portion of rust somewhere that has caused damage or a partial gap, you can fix it up. Follow the three steps below to find out how.

  • Use a wire brush to loosen any rust.
  • Use mineral spirits to remove the grease around the affected area. As you do, that oily stain that the exhaust fumes are causing will clean right up.
  • Put a few coats of a zinc-rich cold galvanizing spray on all of the stubborn rust that wouldn’t lift. Dry it and then put the flue back in place. It will usually take about 30 minutes for it to dry. When you do it this way, you won’t have to worry about rust spreading anywhere else.

Fix the broken flu parts.

Sometimes when there is a lot of dust, the flue can break or the parts can separate. This is one of the most likely causes of exhaust fumes not properly leaving the space.

To fix it, after you have dealt with the rust in step two, seal off the broken areas or leaks. You can patch the leaks using a moldable, small sealant if the cracks are small.

If they are bigger, you might need to add insulation around the entire damaged area. Wrapping the area using roof tape could work well to serve as insulation for the flue duct.

If in the end, you find that the damage is beyond repair, you can simply replace the flue with a brand new one.

how to get rid of car exhaust smell in the house

2. Partially Blocked Airflow

Any interruption in the HVAC system can cause it to malfunction, and in this case, it can start from the reverse directing of these exhaust fumes back into your home.

Besides issues with the actual flue inhibiting the air’s ability to flow out, it can also be the fault of outside elements locking the airflow from the vent.

Some situations that could cause this include:

  • A bird’s nest or similar blockage may have entered the furnace through the duct cap on the roof.

If there is anything hanging in front of it that way, it could direct the exhaust fumes right back into the flue.

  • There could a blockage in the fresh air inlet of the HVAC system you’ve installed, including the furnace, air conditioning, heater or water heater by a bird’s nest, insects and something else.

This will cause weak combustion and only partially blow out the burned gas throughout the rest of the system.

The Fix

The easiest fix is to remove whatever is locking the furnace crown or vents. This can mean a bird’s nest, debris, dust, bugs, and other such contaminants.

Blockage Type 1: Bird/Birds Nest

If the bird’s nest or an alive bird is what’s causing the problem, be careful if you try to extract them.

Wear gloves as you lead the bird out or pick up the nest. There is really no other choice outside of relocating the nest.

Blockage Type 2: Dust and Debris

If dust particles are clogging up the exhaust or inlet, you’ll find that this is common with a higher-efficiency furnace that hasn’t been cleaned for some time.

If any construction on the home took place around it, it is likely that there is construction debris clogging up the ducts.

Fortunately, cleaning out the dust from the inlet is an easy process. Simply follow the steps below:

  1. Find the exit point of the exhaust and intake pipes.
  2. Using a screwdriver, open up the vent pipe.
  3. Pull out any large dirt and debris from it.
  4. Use a soft cloth or brush to remove the stickier debris and dirt.
  5. Use an air duct cleaning vacuum to clean out the whole vent.
  6. Look for any other blockages using a wire hanger that you shape into a shepherd’s crook.
  7. Use the screwdriver to close the pipe back up.

3- Garage Fumes Inside the House

A study done by Health Canada noticed that homes that have an attached garage can bring with it a significant amount of a gasoline pollutant known as benzene.

The Fix

It can be difficult to prevent the fumes from making it into the house through cracks, leaks, and gaps.

If you follow the steps below, you can operate with relative certainty that the gap is closed up.

Seal Garage Cracks on the Ceiling

Take a thorough look around the garage to find any kind of gaps, leaks, cracks, or holes in the garage to the home. This includes looking between non-air-tight doors and the ceiling edges.

If you find any gaps, use putty, caulk, spray foam, weather-stripping, and other materials to seal up the holes.

Finish the Drywall and Ceiling Wall

For any new home, it is common to have drywall and ceilings that have unfinished joints.

These small cracks offer plenty of room for exhaust fumes to move through and need to be taken care of.

In order to remedy this, take an in-depth look at the joints in the drywall to make sure they’re sealed properly with compound and tape. The paint and primer will also need to be checked for leaks as well.

Burn Gas or Oil with Care

Exhaust fumes come from a gas or oil burner that you use in the garage.

In order to prevent the smell and fumes from getting into the house, it’s a good idea to run any engines or power tools as close as you can to the window to help ventilate the space.

Otherwise, use a fan or a separate vent to move it out of the space.

4- From the Neighborhood

Though the possibility is small, there’s a chance that the fumes are coming from the surrounding areas.

You can check for a closely placed exhaust vent somewhere near the wall at the ground level.

If your neighbor has a heating system or furnace that is large enough, there is a chance it could get through the air inlets and cause the smell.

The closer you live to your neighbors, the more likely this could be a problem.

The Fix

You and your neighbor may need to work together to set your two vents, including your inlet and your neighbor’s exhaust, at a distance from each other.

You can also ask them to add ducting atop the exhaust in order to move it towards the roofs instead of your house, since moving your inlet vents is a trickier and more time-consuming process.

How To Stop the Gas From Coming Back Again

If you get rid of the exhaust smell and want to make sure it never returns, there are some steps you can take:

Keep your ventilation system clean.

Residential air ducts are often full of hair, dirt, spider webs, foliage, and other debris. Be sure you clean them on a regular basis, as often as once a month, and you can prevent these blockages.

This will also make your HVAC system run more efficiently, saving you money while also eliminating the risk of exhaust fumes getting into the home.

You can use tools such as a vacuum cleaner, wire brush, cleaning brush, broom, or other such tools to clean it out. If you use a vacuum, be sure it has a long hose that can get deep inside the vents.

This will help remove the mildew and mold buildup inside the duct. You should also be cleaning the grills regularly.

Space Out the Exhaust and Inlet.

To prevent the exhaust from feeding right into the inlet, make sure they aren’t too close to each other.

The inlet can easily suck up what comes out of the vent, even though one points up and one points down. Try to keep them at least five feet apart and keep the area free from clutter.

Keep Your Air Filter Maintained.

Alongside the furnace filter, you’ll also want to clean and maintain your air filter once a month and check for any broken pieces.

Usually, because of poorly fitting filter slots or overuse, air filters can bend or otherwise displace.

If it is positioned this way, it won’t be able to keep the exhaust fumes out. Check for damaged or ill-fitting air filters regularly.

In Conclusion

If you notice a foul exhaust fume smell, it is imperative that you take immediate action; you don’t want the carbon monoxide from the fumes filling up your home and causing you to suffocate.

In this article, we provided four of the most common causes of exhaust fumes getting into your house.

We also offered steps you can take to fix the leak regardless of its source. Finally, we left tips on how to prevent it from coming back.