What Causes My Car Smells Like Gas When I Start it But Goes Away?

My car smells like gas when I start it but goes away; anyone experiencing this should take the issue very seriously and not trivialize the situation by treating it as ‘common’. It is not common, and for a fact, you are not supposed to perceive gasoline fumes in your vehicle in the first place. A gas smell indicates a high possibility that there might be a gas leak in your vehicle.

In some cases, this smell can quickly disappear and is never perceived again. Still, in other cases where the gas odor is constantly perceived each time you enter your vehicle, it signifies a problem with your vehicle. This should be given immediate attention as this might be a severe gas leak.

Gasoline is a highly explosive fluid that is dangerous to your health when its fume is perceived. Hence, If your car has a high gas leakage, it can lead to a tragic situation if not handled properly. Anytime you perceive gas odor in your vehicle, make sure you find out the cause and resolve it as soon as possible.

What causes my car to smell like gas when I start it but goes away

When you notice your car smells of petrol when started, there is a high chance it is as a result of a gas leak, but there are other probable causes that can be responsible for this harmful odor. Let’s review some of the causes that can explain why you are experiencing this:

Exposure to Gas fumes

This is one of the probable causes that can make you perceive gas odor in your vehicle. Most times, when you enter a gas station with your vehicle to refill your fuel tank, the gas smell from the station can penetrate the vehicle through your vehicle’s windows and doors. After you leave the gas station, roll down the window glass and let it stay down for a couple of minutes and then roll it up. If you still perceive gas odor after a few days, then there is something wrong with your vehicle.

Broken gas cap

When you notice your car smells of petrol outside or inside in your vehicle, one of the first areas to check is your vehicle’s gas cap. Each time you take-off the gas cap to open your gas tank for a refill, ensure that you properly tighten it back and check if the cap is still functioning properly. If you forget to do this, gas or gas fumes can easily escape through a loosen or bad gas cap; this can turn on modern vehicles’ engine check light.

Busted Canister

The canister is a component of your vehicle’s emission controls responsible for absorbing gas vapor that would have escaped into the atmosphere; this prevents air pollution. Assuming the canister is faulty and leaks through the vent, you will perceive a strong gas odor in your vehicle. This fault can illuminate the engine check light.

Bad Fuel Injector

When the fuel injector of your vehicle is bad, it can result in gas leaks from its rubber seal or o-ring seal. The fuel injector is designed with o-ring seal at the top of the injector and a rubber seal at the bottom side. These seals can easily be damaged by dryness. To check your vehicle’s fuel injector, you need to open the bonnet of your vehicle and turn on the engine. If you notice fuel around the injector, it might be the cause of the gas smell in your vehicle.

Damaged gas tank

A punctured gas tank is one of the major causes of severe gas leakage, and also, a faulty gas tank vent hose can cause gas to leak from your vehicle in either mist or vapor form. If you discover your vehicle has this fault, make sure you resolve this issue immediately; if ignored, the results can be fatal.

Faulty fuel injection line

The fuel injection enforces high pressure in your vehicle’s fuel lines. This pressure is within the range of 58psi to 128psi. Therefore, when there is a fault in your fuel injection line, it can lead to an intensive gas odor in your vehicle. Any damage to the fuel injection can cause gas leakage from various parts of the line. This can generate a gas smell, which is dangerous to one’s health. It is even more dangerous if the leakage is close to the engine or exhaust of your vehicle.

A torn Fuel Line

The fuel lines in your vehicle are responsible for connecting the fuel tank to the engine. The fuel lines are made of rubber and are located under your vehicle. Hard elements or debris on the road while driving damage the fuel lines and can cause gas leakage under your vehicle. A torn fuel line can affect your vehicle’s engine performance.

Bad pressure regulator

A bad pressure regulator is one of the probable causes that can cause an issue of gas smell in your vehicle. If you have a bad pressure regulator in your vehicle, it can cause the fuel to be burnt until it gets too thin. The process of burning more fuel can accumulate gas fumes in your exhaust, which can penetrate inside your vehicle through the ventilation system. One of the major signs that indicate a bad pressure regulator is a low engine power and gas efficiency.

Ancient vehicles

Commonly, vehicles manufactured in the early 80s are most likely to have a low gas odor after you put off the engine; this is due to the fuel in the float bowl of your vehicle’s carburetor. You will notice the car smells like gas when parked. Afterward, it dissipates. This issue is not found in modern vehicles because of the evaporative emissions system installed in it.

How to fix this issue?

This problem might not always be due to a damaged or faulty component in your vehicle. It might just be due to a loosed or missing gas cap; some individuals sometimes forget to use the gas cap to lock their vehicle’s fuel tank after refueling, leaving the tank covered with just the fuel door, which is not enough to stop the escape of gas fumes.

If this is the issue, you don’t have to repair or change anything. All you need to be concerned about is remembering to always lock your vehicle’s fuel tank with the gas cap, and then you will have no problem.

Having a faulty gas cap is easy to fix. You just need to buy a replacement but make sure you buy the recommended gas cap for your vehicle. Remember always to check the fuel or cap for any faults when you refill in a gas station.

It can be not easy to fix a punctured tank if you are not a mechanic, this process is technical, and it must be done correctly. The fuel tank might need replacement, depending on the extent of the damage. If you want to try a fix, you need to first drain the fuel out from your gas tank; you can use a hose to do this.

Jack up your vehicle; make sure this is done properly. Then crawl under to spot out the area of leak on the tank. You can use sandpaper to mark that area. You need to mix the epoxy; do this with your vehicle’s manufacturer’s guide. Then carefully use a rag and alcohol to clean the sanded area. Apply the mixed epoxy in and around the hole of your gas tank. Then leave it for a few minutes to dry. Then fill up your tank and thoroughly check for leaks again.

To fix a torn fuel line, it is advisable to change the entire damaged fuel line instead of repairing it. To replace a fuel line, you will need to raise your vehicle with a jack gently. Disconnect the fuel connections with a wrench and place a can under to contain the line’s residual fuel.

Grab a screwdriver or other appropriate tools in your tools box to loosen mounting clamps on the fuel line. Inspect the fuel line fittings for any fault; if it is faulty, you need to replace these fittings before you fix the new fuel line. After purchasing the new fuel line, use the same tools to fix it to your vehicle properly.

For a busted canister, you need to remove the canister connections from your vehicle with a wrench. The charcoal canister is located under the bonnet of your vehicle. Check the o-ring and rubber seal on both ends of the canister; if loosed or damaged, replace the seal.

Make sure you properly clean dirt or debris on the connection areas before replacing the seals; failure to do this can still cause the seals to leak gas. If the canister is broken, you need to also replace it with the right canister for your vehicle.

Why Your Car Smells Like Gasoline YouTube

FAQs

Q: Why does my car smell like gas when I start it?

There are a few reasons why you perceive gas fumes in your car, but a gas leakage is considered the most probable cause concerning this issue. Gas leakage can result from a faulty gas cap, damaged fuel line or tank, and a busted canister. You might also consider checking the environment where your vehicle is parked.

Q: Why does my car smell like gas but no leaks?

If you constantly perceive gas fumes in your vehicle, know that there is a high chance that there is a gas leak in your vehicle, even if you cannot see the leak. You need to look for signs that reflect gas leakage and then thoroughly investigate the cause of the smell, and you need to do this fast. First, check for minor causes like an open gas tank or a faulty gas cap.

Also, examine your environment for gas odor. Problems with your vehicle’s fuel system or the engine can cause severe gas leakage from your vehicle.

Q: Is it Ok for my car to smell like gas after the fuel pump has been replaced?

It is not normal to perceive gas fumes after you just replaced the fuel pump in your vehicle. This happening shows that there might still be a gas leak, and it needs repair. When you change your fuel pump, it is advisable to change the filter simultaneously. This is because the old filter might not be able to handle the flow pressure of the new pump.

Also, check the areas of connection where you fixed the new pump. There might be a gas leak from those areas. You can jack up the back of your vehicle to properly check the fuel pump connection areas.

Q: Should I be worried if I drive a car that smells like gas?

It is lethal to drive a car that smells like gas; the gas is flammable, and it is not good to inhale the fumes. A gas leak can cause your vehicle to explode due to the fact that the gas is highly flammable. Gas leakage in a vehicle puts both the lives of the driver and the passengers in danger. So you should not drive a car that has gas smells. Investigate and locate the cause of the smell before you decide if it is safe for you to drive your vehicle or not.

Q: Can a bad O2 sensor cause a gas smell?

The oxygen sensor, also referred to as the O2 sensor, is found inside your vehicle’s exhaust manifold. It helps keep track of the oxygen level in your exhaust and send the signal to the ECU. If the oxygen sensor is faulty, it can lead to an imbalance of the air-fuel ratio of your vehicle, which means that there will be an increase in the level of fuel consumption.

You might not perceive gas smell if this sensor is faulty, but if you notice a pungent smell coming out from the exhaust, it signals a bad O2 sensor.

Final Words

Now you are aware of what to do if anyone says, “my car smells like gas when I start it but it goes away,” how to educate them on the probable causes and how they should effectively handle the issue. Please attend to this problem immediately, if noticed. Also, ensure you regularly examine your vehicle for any faults, and if you find any, repair it as soon as possible.
If you have any uncertainties regarding this article or other related articles, leave a comment, and we will be sure to help.

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Osuagwu Solomon

Osuagwu Solomon is a seasoned automotive technician for the past 9 years, and a technical writer. He loves writing about auto professional repair guides, DIY repair guides, and buyer’s guide. After spending six years in the automotive workshop, he decided to impact his knowledge to people aside his domain, and he has achieved this by centering his Automotive writing skills on REPAIRS.

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