Why do spark plugs smell like gas? Causes and solutions

Cars are often powered by gasoline fuel, which produces an unpleasant smell. While driving a car, the gasoline smell is a smell that you shouldn’t ignore.

While the gas smell is common, especially with your car’s spark plugs, it is always advisable to find the source or why the spark plugs are smelling. So why are the spark plugs smelling like gas?

So, why do spark plugs smell like gas?

A gas smell can be so dangerous and annoying at the same time. So it is not something you can easily ignore wherever it happens.

There are several reasons why spark plugs might smell like gas, but generally, a gas-smelly spark plug indicates a faulty car part. The gas-like smell will not just come out if there is a damaged part.

So it is essential whenever your car’s spark plugs produce that gas-like smell to inspect your whole car to find out what the problem is. In most cases, the major reason why the spark plugs can smell like gas is that they are loose or damaged.

Causes and solutions to why spark plugs smell like gas

When a spark plug smells like gas, it means that there is a part of the car that is damaged. However, several parts can come into contact with the fuel, so it is essential to check out.

Gasoline is the fuel that your car uses. Once you pump a liquid gas, the engine turns it into explosive vapor, which moves the vehicle. It is during this process that the smell of gas can be felt. So why does this happen?

1. Loose spark plugs

Loose spark plugs could be the reason why they smell like gas. If the spark plugs are not tightened to the correct torque, they could become loose over time.

So, since the sealing ring around the spark plugs is not correctly seated, the spark plugs could smell like gas. If the fumes get out of the combustion chamber, they will get to the air intake of the car’s HVAC system.

The motor will spew the gas fumes into the air vents. Spark plugs often have washers on the threaded part to seal everything. Therefore, if the washers are missing, broken, or cracked, the gas smell will be coming out.

Troubleshoot and Solution

Inspect the spark plugs to ascertain if they have any anomaly. Just inspect them one by one to avoid mixing them up when reinstalling them. Check if everything is okay, or if there is no problem, check the torque.

To do this, loosen the spark plugs. After this, you will need to screw them back by using your hands until they get back to the right torque.

2. Faulty gasket or O-ring around the Oil Cap

This is the most common reason your car’s spark plug can smell like gas. The oil cap is the oil reservoir cap, the part that’s taken off while changing oil. If the lid is not correctly sealed, the gas and oil fumes will escape and find their way out.


To solve this, you need to locate the cap and inspect any oil stains and dirt. If the lid has those stains, then it means that the cap is not correctly sealed.

You can take off the cap and check the O-ring below it. If the O-ring is missing, flattened, or cracked, you will have to replace it. Likewise, seal or make replacements accordingly if the cap is busted or broken or not properly sealed.

While returning, ensure you find a cap that perfectly fits the size of the damaged one.

3. Failed distributor or ignition

The distributor and ignition coils supply electrical current to the spark plugs for a spark to occur. If the distributor or the coil fails, the spark might be too cold to ignite the fuel in the combustion chamber. When this happens, the result is a gasoline smell from the spark plugs.


When this happens, find the cause for the failed ignition and make replacements if necessary.

4. Sunken engine

Spark plugs are meant to be dry for the continuous production of sparks. But when the engine is sunken, the spark plugs will get soaked with gas hence a gas smell.


An engine’s internal combustion needs a precise mixture of air and fuel to run correctly. But when this is in excess, severe issues can happen, like having the spark plugs smell like gas.

Reasons for this; include worn-out spark plugs, failed distributor or ignition coil, and a leaking carburetor. To ascertain the primary cause, carry out some troubleshooting for the possible problems for necessary amendments.

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