Why My Car Smells Like Gas When I Start It But Goes Away?

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When your vehicle smells like gas, this is not something to be ignored because this is abnormal and often results from an underlying issue.

You should know that gas fumes should not be present in your car’s engine, and whenever you experience these, you should get these checked to see what the issue is and get that fixed.

If you are trying to find out why does my car smells like gas when I start it but goes away?

Then these reasons are why you may be facing:

  1. Being Exposed To Fumes Of Gas
  2. Your Gas Cap Getting Broken
  3. A Damaged Gas Tank
  4. A Faulty Fuel Injector
  5. Busted Canister
  6. Torn Fuel Line
  7. Fault In The Fuel Injection Line
  8. Faulty Pressure Regulator
  9. Using An Old Vehicle

I will explain all of the reasons for the leaking of gas with detail and what you can do to fix this issue, which should be done as soon as possible as this is a sign of a damaged engine.

Why Do I Smell Gas When I Start My Car?

Is it safe to drive a car that smells like gas? Let's find out

As I have already mentioned, if your car ever does smell like gas, then this is an indication for you to get it checked immediately and then fixed.

Sometimes, the smell can some for some time but go away quickly and never come again.

However, if the gas comes every time you start your car, then that means you should get it fixed immediately because this is the issue.

A huge gas leak might be happening in your engine. It should be noted that gasoline is very explosive and dangerous for your health.

For this reason, if there is a big gas leakage in your car, some dangerous situations might arise, as there is always a danger of explosion.

It, therefore, makes it essential to find a solution. You should get it fixed by an experienced mechanic as soon as possible.

Here, I will talk about some reasons that might cause the gas leak inside your car to happen.

1. Being Exposed To Fumes Of Gas

This is a reason cause the gas odor feels like it is coming out of the car. However, there might be another reason for this.

Sometimes, when you go to the gas station to get the fuel tank refilled, you might be able to smell the gas in the station as it might penetrate through the windows of your car.

This might cause the gas smell to get inside the vehicle. For this reason, you should roll down the windows whenever you get out of the gas station and then roll them up later on.

However, if you can still smell the gas after some days, you might need to get that checked because this would mean something is wrong with the engine.

However, you should know that not every time your car smells like gas that there is an issue with your vehicle.

2. Your Gas Cap Getting Broken

When the odor of the gas fumes come, the first you should be checking is the gas cap.

Every time that the gas tank is opened for refilling, you should get it tightened back properly and see if the can is functioning properly after that.

If you don’t do this, then the gas fumes or the gas can get out of the loose areas of the gas cap. This might turn on the engines of modern vehicles check light.

Therefore, it is essential to properly secure the gas cap every time you refill the tank, as not doing so will cause gas leaks, which can be very dangerous.

3. A Damaged Gas Tank

If your gas tank is punctured, severe leakage might occur.

This can cause the odor to come out of your vehicle. In addition, if the vent hose of your gas tank is faulty, this can also cause gas leakage.

This will be in either vapor or mist form. If this happens, get the issue fixed immediately because lack of doing so may result in fatal results.

The gas tank can get punctured due to several reasons. Among these are if an undercoating has been installed in your car.

An undercoat is a paraffin-based spray-on coating that holds salt and other metal-eating chemicals.

Therefore, rust-out holes can appear. If your car goes ahead and hits a large pothole or a rock, that might also cause the tank to get punctured.

4. A Faulty Fuel Injector

If the fuel injector in your vehicle turns bad, then gas leaks might happen from the o ring seal or the rubber seal.

This is on the injector’s top, plus a rubber seal is placed on the bottom. Dryness can easily cause these seals to get damaged.

If you have to be checking the fuel injector of your vehicle, you have to open the car’s bonnet and then turn the engine on.

If any fuel is noticed around the injector, then this might be what is causing the smell of gas. Not only this, if the fuel injector is bad, then the fuel economy of your vehicle can drop a lot.

The ECU calls for much more fuel from the injector, but this doesn’t go to the combustion chamber.

Therefore, the lesser the fuel that gets to the engine, the lower the fuel economy. For these reasons, you should get the fuel injector fixed as soon as possible.

5. Busted Canister

A part of the engine’s emission control is the canister.

This absorbs any gas vapor that escapes into the atmosphere, preventing it from polluting the air. If the canister is damaged, there might be leakage from the vent.

This will cause a strong odor in the vehicle. This is dangerous as the engine check light might get illuminated. Therefore this issue should also be resolved as soon as possible.

6. Torn Fuel Line

Your vehicle’s fuel lines connect the fuel tank with the engine. These have a rubber build and are placed under the vehicle.

Debris or any hard elements on the road when driving your vehicle might cause the fuel lines to get damaged.

This might cause gas leakage under the vehicle. This might negatively affect your vehicle’s engine performance, as the engine will not work as efficiently.

This might cause your car to not run as well as usual and create problems for you. Therefore this issue needs to get fixed as soon as possible as well.

7. Fault In The Fuel Injection Line

High pressure is enforced on the fuel lines of your vehicle by the fuel injection. The pressure range of this is between 58psi to 128psi.

For this reason, whenever the fuel injection line faults it, there might be a lot of odor coming out of the engine.

If the fuel injection gets damaged in any area, then gas leakage will occur from many fuel injection line areas. The smell of gas will come, which is hazardous for health if breathed.

In case the leakage happens somewhere near the exhaust or the engine of your vehicle, this can be even more dangerous, as there is always a danger of inflammation, which can be fatal in some cases.

8. Faulty Pressure Regulator

This is another reason that might cause the vehicle to smell like gas. If the pressure regulator inside the vehicle is bad, then the fuel will burn itself until it becomes too thin.

This causes more fuel to get burned. This process of getting more fuel burnt will cause gas fumes to accumulate in your car’s exhaust.

These can easily penetrate your vehicle from the ventilation. If your engine has low gas efficiency or engine power, that might signify your pressure regulator being damaged.

If it is damaged, this might cause a faulty fuel pressure; therefore, there will always be a risk of misfires, power and acceleration reducing, and the fuel efficiency getting dropped.

If you experience any of these symptoms, then it might mean that the pressure regulator is bad.

However, these symptoms are also caused due to many other reasons; therefore, a check-up by a professional is necessary, after which you should get the issue fixed.

9. Using An Old Vehicle

If you use an ancient vehicle, i.e., one made in the early 80s in this case, then this might be the reason you experience the gas smell whenever you turn the engine on.

This is because of the fuel present in the vehicle’s carburetor’s float bowl.

You might notice the vehicle smelling like gas whenever it is parked in this case, and it might go away after some time.

Modern vehicles do not have this issue because evaporative emissions systems are installed.

Therefore, if your vehicle is ancient, then this might be the most likely reason, and there is nothing to worry about in this case.

How To Deal With This Problem

You should be aware that your vehicle smelling like gas does not always mean that there is a vehicle component which is damaged or faulty.

This could also be because of any caps being loose, which might cause the gas to leak out easily, causing the smell.

Many people forget to secure these caps on their fuel tank of the vehicle after refueling.

Then, the tank is covered by only a fuel door, and this will still let the gas fumes escape from the tank easily.

Securing The Fuel Tank With Gas Cap

If this is what is causing the problem, nothing needs to be changed or replaced, just pay more attention when securing the fuel tank using the gas cap.

The gas cap could be faulty, and getting this fixed is also pretty easy.

You can get by a replacement in this case but remember to buy the proper one which is recommended for your vehicle’s model.

Whenever you get a refill at the gas station, remember to check the cap or fuel if they have any faults in them.

Fixing The Punctured Tank

However, if the tank is punctured, getting it fixed by yourself will not be easy at all as you aren’t a mechanic.

The process for getting the punctured tank fixed is very technical and requires the skills of an experienced person.

Therefore the best option is to get it done at a mechanic’s. It depends on how much damage has happened to your vehicle, but you might have to replace the fuel tank.

If you wish to fix it, you should first be:

  1. Draining the fuel from the gas tank by using a hose.
  2. Next is to jack your vehicle up properly and get under the car to see which area leaks.
  3. Then, you can mark this area. Using sandpaper will help.
  4. After this, you have to be mixing the epoxy.
  5. When doing this, you need to see the vehicle’s guide provided to you by the manufacturer.
  6. Then, you have to clean the area which is sanded using a rag dipped in alcohol, and then let this dry for some minutes.
  7. You can check if it still leaks by filling the tank up and seeing if the leakage is still happening.

Change The Fuel Line

If your vehicle’s fuel line is torn, then the best option would be to get the whole fuel line changed rather than trying to get this repaired as it is damaged.

To do this:

  1. You have to raise the vehicle using a jack.
  2. After this, you have to disconnect all fuel connections with a wrench, then to help control the residual fuel of the line, put a can under it.
  3. Then, get yourself some helpful tools such as the screwdriver and then loosen the mounting clamps that are on the fuel line.
  4. Afterwards, check the fitting of the fuel lines for if they have any problems.
  5. If there are any faults, you’ll have to replace the fittings before fixing the fuel line.
  6. Then, buy yourself a newer fuel line and use your tools to help fix this onto your vehicle properly.

If The Canister Is Busted

If the canister is busted, then first remove the connections of the canister in the vehicle using a wrench. A charcoal canister will be present under the vehicle’s bonnet.

You have to first be checking the o–ring as well as the rubber seals on the canister’s two ends, and if the seal is damaged or loose, then replace it.

Before you replace the seals, remember to make sure that the debris and dirt on the areas of connection are cleaned properly.

If you don’t do this, the seals might start leaking gas. If your canister has broken, this can also be replaced by getting the appropriate one for your vehicle’s model.

Frequently Asked Questions

Q1. Why Does My Car Smell Like Gas After Replacing The Fuel Pump?

After replacing the fuel pump, if your vehicle smells like gas, it should be noted that this is not normal.

This might show that the gas leak is still happening, which is an issue that needs repairing.

Therefore, when changing the fuel pump, you should remember that you change its filter as well.

The reason for this being done is that with the older filter it will not be able to handle the low pressure of the newer pump.

Moreover, you should check all the places where the new pump has been fixed, as the gas might be leaking from these areas. To easily do this, the vehicle’s back can be jacked up.

Q2. Should I Drive My Car If It Is Smelling Like Gas?

No, as gas is flammable, it is quite dangerous for you to be going around with your car to smell like gas.

In addition, inhaling these fumes is also injurious to health; therefore, driving a car around smelling like gas is very bad for the environment.

The most dangerous outcome of doing this is an explosion because gas is so flammable. Therefore, with gas leaking in the car, the passenger’s and driver’s lives are not safe.

Therefore, avoid ever driving your car fit starts to smell like gas, and see what can be done to get the issue fixed as soon as possible, as many dangerous outcomes could come from ignoring gas leaks.

Q3. If My O2 Sensor Is Bad, Can This Smell Like Gas?

An O2 sensor or an oxygen sensor is present in your vehicle’s exhaust manifold.

This will help keep the level of oxygen of your vehicle’s exhaust on track and then a signal will be sent to the ECU.

If the oxygen sensor has a fault, an imbalance of the ratio of air and fuel might occur, and this might cause the fuel consumption level to increase.

This is bad as it will affect fuel efficiency quite negatively. It should be noted that if the sensor has a fault, it will not cause gas smells.

However, if the smell is coming out of the exhaust, this could be due to the O2 sensor being bad.


I hope you’ve found your answer to why does my car smells like gas when I start it but goes away.

If you ever notice this happening, you must check the problem as quickly as possible.

Firstly, the reasons that might cause the gas to leak might also mean that the engine’s efficiency is greatly affected.

Secondly, going around with gas leaks is bad for the environment and highly hazardous as gas is flammable.

You have to examine the problems with your vehicle as quick as you can and either repair these issues yourself or get this done at a professional’s.