If you’ve noticed a distinct odor of gas coming from your engine oil, you have a reason to be concerned. If your oil smells like gas, it means a lot of gasoline is mixed with the oil.
Although it’s quite common to smell gas when changing engine oil, a strong smell of gas in the oil indicates an underlying issue that requires attention.
The gas-oil mixture could be caused by worn-out piston rings, faulty fuel injectors, or driving for short distances on most occasions.
In this article, we will explore the potential reasons for gas-oil mixtures, how to fix the problem, and more.
Symptoms of an Oil-Gas Mixture
If your engine oil has mixed with gasoline, there are several signs and symptoms that can indicate this issue. They include:
Strong Gasoline Smell
Gasoline has a distinctive and strong smell that differs from typical engine oil. If you detect a strong gasoline smell when running the engine or checking the oil, chances are, your oil is contaminated with gasoline.
White Smoke
If your engine oil is contaminated with gasoline, it will produce white smoke from the exhaust when burned in the combustion chamber. The smoke may have a noticeable gasoline odor.
Increased Oil Level
Your engine should not increase at any time. In fact, the oil level should drop the more you use your vehicle.
If you notice that the oil level on the dipstick is higher than normal, it means some fluid has made its way into the oil pan. The fluids can either be gasoline or water.
You can tell whether your oil is gas or water contaminated by checking the color and consistency. Water-contaminated oil appears milky or frothy. On the other hand, gasoline-contaminated oil has a thinner consistency.
Diluted Oil
Gasoline is thinner than engine oil. As such, when it mixes with the oil, it dilutes it. This changes the consistency and viscosity of the oil, making it thinner and less effective in lubricating engine components.
If you check the oil on your dipstick and notice that it has a brighter color or appears thinner than usual, it could indicate a mixture of engine oil and gasoline.
Engine Performance Issues
If oil is contaminated with gasoline, it can affect the engine’s performance. You may experience symptoms such as rough idling, engine misfires, or decreased power.
The presence of gasoline in the oil can also compromise the lubricating properties, leading to increased wear on engine components.
What Causes Engine Oil to Smell Like Gas?
There are several possible reasons why engine oil can smell like gas. Discussed below are some of the most common:
Worn Piston Rings
Piston rings help seal the combustion chamber. If worn out or damaged, they can leak gasoline into the oil. This can make your oil smell like gas.
Faulty Fuel Injectors
A faulty fuel injector can allow excessive fuel into the combustion chamber. Over time, this fuel can seep past piston rings and contaminate oil in the oil pan, causing a gas-like smell.
Fuel injectors can also become stuck open, allowing excess fuel to pour into the combustion walls when the engine is not running. The excessive flow can lead to fuel pooling in the cylinder walls and eventually mixing with the oil.
Carburetor Problems
While modern cars use fuel injectors to supply the engine with fuel, older ones use carburetors. Your oil will smell like gas if any of your carburetor parts malfunctions.
A faulty carburetor can develop issues like leaking fuel or a stuck float valve. Should this happen, the fuel can bypass the intended pathway and enter the intake manifold or engine’s cylinder.
From there, the fuel can enter the crankcase, mixing with engine oil.
Engine Misfires
If an engine misfires, the fuel is not completely burned. Unburned fuel can flow into the crankcase and mix with the engine oil, causing it to smell like gas.
Delayed Oil Change
If some fuel enters the oil system because of a leaky fuel line or a faulty fuel injector, it can cause the oil to smell like gas.
When the oil change is delayed, the contaminated oil remains in the engine for an extended period, intensifying the gas smell.
Frequent Short Distance Drives
When you drive your car for short distances, the engine may not fully heat up. As such, the fuel combustion may be incomplete, resulting in unburned fuel entering the engine oil.
Furthermore, during short-distance drives, blow-by-gases (a mixture of gases that leak through piston rings and enter the crankcase) may contain fuel vapors that combine with the engine oil, making it smell like gas.
Using Gas Instead of Oil
Although this is uncommon, mistakes happen, especially if you are not careful enough. You can accidentally pour gas into the engine oil port instead of the oil. This usually happens when you mix up containers.
How Can You Fix Oil Smelling Like Gas?
If you are experiencing an issue where your engine oil smells like gas, it could mean there is a problem with your vehicle’s engine or fuel system.
Here are several steps you can take to solve the issue:
Identify the Source
Find out whether the gas smell is coming from the engine oil or another part of the vehicle. This will help you narrow down the potential causes.
Check for Fuel Leaks
Inspect the fuel system for leaks. Look for fuel signs or wet spots around the fuel pump, fuel injectors, fuel lines, or carburetor. Repair or replace any affected component.
Monitor Fuel Consumption
Keep a keen eye on your vehicle’s oil consumption. If you notice a sudden increase in the oil level on your dipstick, it could indicate there’s a leak.
Avoid Short Drives
Long drives allow the engine to reach its optimal operating temperature. This way, the fuel burns completely during combustion, reducing the chances of fuel dilution and your oil smelling like gas.
Longer drives allow the engine to warm up and burn off any excess fuel.
Regular Maintenance
Regular maintenance practices such as following the recommended oil change intervals can also prevent oil-gas mixture. If you notice a persistent gas smell in your oil, have your vehicle inspected by a qualified mechanic.
Is it safe to drive your car if you smell gas in your engine oil?
It is unsafe to drive your car if you smell gas in your engine oil. The presence of gas in the oil could indicate a problem with your car’s fuel system, such as damaged piston rings, faulty fuel injectors, or a leaking fuel injector.
Driving under such circumstances can be dangerous, leading to engine damage, fire hazard, or poor engine performance.
Should motor oil smell like gas?
Motor oil should not smell like gas. If you detect a strong gasoline smell in your oil, address the situation promptly to prevent engine damage and safety hazards.
Is it bad if your engine oil smells like gas?
Yes, it is bad if engine oil smells like gas as this could indicate a problem with your vehicle.
Can gas in oil cause low oil pressure?
Yes, gasoline in engine oil can lower the oil pressure in an engine. When gas mixes with the oil, it can cause air pockets, which reduce the oil’s lubrication properties.
Air pockets or foam in the oil can cause reduced oil pressure because the air compresses more easily than oil.
As such, when the oil pump tries to circulate the oil, it encounters resistance from the air pockets, leading to low oil pressure.
Conclusion
If you notice a strong smell of gas in your oil, address the issue as soon as possible. Visit a qualified and certified mechanic to diagnose and repair the damaged or worn-out components to prevent further engine damage.
