Is my oil smelling like gasoline? Do I need to be worried?

Do you notice a strong gas smell in your oil dipstick when it comes to engine oil? It is a very common issue with gas engine. How serious is the problem? And should you do anything about it?

The following article will discuss why oil smells similar to gas, and ways you can prevent it from happening again. If you drive only short distances it will not be a problem, but it should alarmize you if this happens more often.

Why does oil smell like gasoline?

Your oil may smell like gasoline if you only drive short distances. You may also experience a rich fuel-fuel mixture, which can be caused either by misfires or faulty fuel injectors.

Another obvious reason is just that you haven’t changed your engine oil for a while. You may notice oil that smells like gasoline after you haven't been following your oil schedule.

Now you got some quick information about it may happen, but let’s go a little deeper into them. This is an in-depth list that explains why engine oil smells similar to gas.

The Causes of oil smelling like gas

1. The air-fuel mixture is too sweet

You have a too-rich fuel mixture, and this is why you gas can get into your engine oil.

If your fuel mixture is too rich, the combustion chamber won’t ignite all of the fuel, and this will cause the fuel to run through the piston rings down into the oil pan.

It could be that the fuel mixture is too rich due to a variety of sensors and other issues. Read the trouble codes with an OBD2 scanner to see if any stored trouble codes could indicate where you should start your troubleshooting.

To learn more, see our article Why is your engine running rich.

2. Only short trips are possible with a car

Most cars have gas running through their oil pans, and it is almost always there. Gas will escape as a vapor when your oil temperature is high.

You will need to fill your tank with gasoline if you drive only short distances.

Replace your oil filter and engine oil if this occurs. If you know that you often only drive for shorter distances, it’s recommended to change the engine oil at shorter intervals than normal.

3. Failures

Misfires are caused by the mixture of air and fuel not being ignited properly or the combustion cycle is disrupted. The gas may wash the cylinder walls if the mixture of air and fuel isn't getting ignited properly. This will result in lower compression, more blow-by to the piston rings, and a Misfire.

The gas can flow through the piston rings and into your oil pan.

Learn more about misfires: Misfire causes and symptoms

4. Fuel injector problem in older cars

The fuel injection vehicles are equipped with small injectors that supply the engine the fuel it requires. This solenoid is used to control the injectors. It's further controlled by a computer that allows the right amount fuel into each cylinder.

Because solenoids work mechanically, malfunctions are possible. Because the material is liquidy, it can get stuck and mix with oil.

The gasoline that is emitted in excess will seep into the oil pan, where it will mix with other oil.

5. Older cars with faulty carburetor settings or other problems

Cars equipped with carburetors have different characteristics. These cars have different carburetors. The diaphragm is responsible for the control of fuel. The gas pedal controls the airflow. Because the gas pedal is mechanically controlled, the valve controlling the airflow may get jammed, which allows the fuel to enter according the mix ratio.

It will cause the problem by allowing gas into the oil. Excessive gasoline, just like in fuel-injected vehicles, will get into the oil pan where it mixes with the oil.

6. Poor piston rings

Bad piston rings can cause more fuel to run into the engine's combustion chamber and the oil pan. However, this is not a very common problem, and it’s tough to repair because you have to take the whole engine apart, so I recommend checking the other things on this list before.

One way to inspect the piston rings, is to perform a Compression test or leak-down tests. More information can be found in the other article Bad piston rings can cause problems.

7. There is no oil change for awhile

There might not be anything wrong with your vehicle, other than you haven’t changed your engine oil for a while.

It can smell very similar to gas if your engine oil has lots of sluggish. If you know that you haven’t changed your engine oil in a while, it is time to do it.

You may not know if your engine oil has been changed recently. Check your service manual, or contact an authorized dealer.