If your engine oil smells like gas, don’t ignore it because this is not how it should smell. Most likely, your motor oil has been contaminated with gas, which can cause major damage to your engine oil.  

Oil is drawn from the sump via pipelines and is frequently used in engines to ensure optimum lubrication and controlled heating. Whereas gas is stored in the fuel tank, it is then transported to the combustion chambers, where it is burned and used to power the vehicle. 

Combining both is extremely dangerous for your vehicle’s overall performance. The oil-gas mixture may occur if you travel for shorter distances more frequently or if your engine components are damaged. 

This article will look into possible causes of your car’s engine oil smelling like gas.  

Why Does My Oil Smell Like Gas? 

Your engine oil may smell like gas because it has been mixed with your engine’s fuel. You can examine the viscosity of your oil to see if it has any gasoline impurities. Rub some oil between your fingers. If the oil seems thin and light, it is most likely contaminated with fuel. Another sign of a gas-oil mixture is white smoke coming from your engine after driving. 

Side Effects of the Oil-Gas mixture:

  1. Decreased performance and lubrication  
  2. It can lead to some unwanted noises.  
  3. Wear-tear in various parts of the engine. 
  4. A gas-oil mixture can cause oil viscosity to thin, making it unsuitable to be used in hot temperatures. 

Causes of Why Your Oil Smells Like Gas 

If your oil tank smells like gasoline, there are several factors to consider. Both gasoline and oil are vital fluids for your car, but mixing them significantly reduces their benefits. 

One of the most unusual situations is when you accidentally put some gasoline in your oil tank. In such an instance, drain all the oil via the drain filter and replace it with fresh engine oil.

Let’s look at some of the most common causes of oil-gas mixtures.

Frequent Short Distance Travel 

When the engine starts, it is intended to run for a longer distance and adjust its odometer and performance requirements accordingly. If the oil and fuel are left unused after the engine has been run down, they are likely to mix. As a result, you are more likely to detect gas emanating from your crankcase. 

Only after the crankcase is heated can the excess fuel stored in it be vaporized. Crankcases usually get heated by driving long distances daily. Having short drives more frequently can result in gas dilution in the oil. Driving a combustion engine for a short distance does not reach its optimal temperature and viscosity. Oil also provides better lubrication and performance to the engine when heated up. 

Make it a point to take a long drive once in a while. If you cannot drive for that long, ensure your engine is warmed up for a few minutes before the ride. If you frequently drive short distances, change your engine oil after some time. 

Damaged PCV Valve

The PCV valve (Positive Crankcase Ventilation) is in charge of returning excess fuel to the combustion chamber rather than storing it in the crankcase. They are also in charge of introducing filtered air into the gas to maintain the air-fuel ratio. 

Sludge formation in the PCV valve can cause it to work inefficiently. As there is no necessary blockage for gas to reach the oil tank, this can result in an oil-gas mixture. Increased pressure buildup within the crankcase can also result in blown gaskets. 

Replacing the PCV valve is the best advice I can give you because it is the most important part of separating the oil from the gas.  The PCV valve is located near the intake manifold or the engine oil cap. Simply locate and replace the new PCV valve based on your engine model. You must replace your PCV valve every 20,000 to 50,000 miles.

Wear-Tear in Piston Rings 

Internal component wear can cause gas dilution in your engine oil. Piston rings are in charge of preventing oil from entering the combustion chamber. It also prevents fuel from getting stored in the crankcase. Piston rings can get damaged due to regular wear and tear in the engine. As a result, the oil and fuel mix in the crankcase, causing your oil to smell like gas. 

Change your engine oil more frequently and use an oil filter to prevent the wearing of the piston ring. 

Sensor Failure

If your oil regulation sensors, such as the O2, MAF, and MAP sensors, are defective, this could result in fuel richness. MAF sensors measure the amount of air that enters the intake system, whereas O2 sensors measure the amount of exhaust fumes. These sensors monitor the air-fuel ratio in your gas and report the results to the electronic control unit.

Rich fuel indicates that the fuel-to-air ratio used within proportion is very high. The ideal gas-to-air ratio is 15:1, but faulty oil sensors can cause the fuel-air ratio to be incorrect. Rich fuel can cause oil to smell like gas because it may cause it to burn incorrectly and possibly contaminate your oil

Engine Misfire

Engine misfire occurs when your vehicle does not start or stop in the middle of a drive. When the engine misfires, a batch of fuel goes unburned and can get stored in the crankcase. Because the fuel is not completely burned, some of it ends up mixing with oil through the piston rings. This can happen due to malfunctioning in ignition coils or faulty spark plug wires.  

Some Methods For Avoiding Engine Misfire: 

  • The use of high-quality motor oil. 
  • Start the car a few minutes before driving to generate heat and clean the spark plug threads off any oil
  • Have your vehicle serviced regularly. 

Faulty Injectors 

Fuel injectors are responsible for providing gas to the combustion engine in the right proportion of air and fuel. They are operated by a solenoid controlled by a computer in your car. Carbon buildup around the fuel injector can cause it to malfunction. If the fuel injector is damaged, it can lead to excess fuel in the crankcase. Excess gas in the crankcase can then combine with the oil, resulting in a gas-like odor in your oil. 

You can use high-quality engine oil to keep your fuel injector from wearing out. Change your engine oil daily to prevent corrosion in the fuel injectors. 


So, to conclude, if your engine oil smells like gas, investigate the cause rather than ignoring the issue. If an internal component is damaged, contact your mechanic immediately and have it repaired. Take your car on a long ride every now and then, as this can help to remove impurities from your oil.  

Drain your old oil and refill it with high-quality engine oil. Avoid local or low-cost oil and oil filter brands because they tend to blend other liquids with your engine oil to save money. If you notice a gas odor from oil more frequently than usual, get a full body inspection on your car. 

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