Why Is There Oil on the Spark Plug?

It’s upsetting to see oils on your spark plugs, but don’t worry too much about it. Let’s take a look in this article at the usual causes of oil leaks inside your spark plug wells. Get to know also how to appropriately identify its main cause. It’s not always as bad as you may think it is.

How does a spark plug work？

Basically, as the name itself says, spark plugs are the spark of electricity that ignites the combustion needed to start your vehicle. To simply describe, a spark plug creates an artificial bolt of lightning inside the combustion chamber (cylinder head) of the engine. It transmits high-voltage energy to create a spark which lights the fire inside the combustion chamber.  

What causes oil on spark plugs?

Gasoline or the oxygen in the air that comes into the engine can burn easily but not like oil. When oil reaches the spark plug, a condition known as oil-fouled spark plug occurs. Oil is a crucial lubricant in a well-functioning engine, but your spark plug isn’t the place where it should be.

There are a lot of causes for oil leakage on your spark plugs. The following are the most common reasons:

•       Ruined Intake Valve Seal

If intake valves get ruined, motor oil can get through the crankcase combustion since these valves regulate fuel and air inflow while managing outflow of the exhaust. It can lead to oil foul in your spark plug well.

•       Damaged Piston Rings

When your piston rings get damaged, preventing oil from getting into the spark plug will be impossible. The function of piston rings in an internal combustion’s pistons is to block the oil from getting into the combustion chamber, and also to get rid of excess oil from the walls of the cylinder.

•       O-Ring Seal Issue

Most of the reasons why there’s oil on spark plugs is the leak on O-Ring Seals. This seal keeps the engine oil, coolant, and other things intact on one side of your spark plugs. O-Ring Seal’s function is to keep them dry. If these seals leak, engine oil can enter into the spark plugs.

Effects of Oil on Spark Plugs

It’s not that hard to notice if there’s oil on your spark plugs. Usually, when oil enters into the combustion chamber, it starts from a small amount and then gets more over time. Here are the effects of oil on your spark plugs:

• The oil substances that enter the spark plugs can’t be burned, so it interferes with the flow of electricity between the electrodes.
• Then it would create a misfire in that particular cylinder. Misfire causes a power loss and fuel efficiency will be lessened.
• Also, oil-damaged spark plugs can make the engine harder to start. It can mess up the acceleration, and might potentially lead to a bigger engine problem.
• Not only does it affect the vehicle’s performance, but it also affects the emissions.
• Oil on spark plugs can create chemical byproducts that are bad for the ecosystem.

How to fix oil problems on spark plugs?

There are many ways to fix oil problems on your spark plugs. To do it properly, follow the steps below:

• Remove each coil pack or spark plug cable. Detach the damaged spark plugs by using a spark plug socket wrench.
• Use a less amount of brake cleaner to minimize the oil, then you can soak up any contaminant.
• Use an extension or other elongated tool to tuck the towel into the spark plug well.
• Let the excess oil soak up for 10-20 minutes by leaving the towel in place.

FAQs

How do you keep spark plugs in good condition?

You can maintain your spark plugs’ good condition by always getting rid of any debris on the exterior part of the spark plug. You can do it by using a sandpaper to gently remove any buildup. Be careful not to damage the metal.

How can you prevent oil leaks on spark plugs?

To avoid oil leaking into your spark plugs, always replace your valve cover gasket, PVC valve, and valve steam seal based on the recommended intervals.

Can I drive with oil on my spark plugs?

You can still drive with oil on your spark plugs. However, ignoring an oil-fouled spark plug may lead to a potential engine damage and ruin components such as catalytic converters.

Conclusion

Spark plug threads and plug wells must be the last places where oil should be. Oil-fouled spark plugs are very noticeable, so you must not ignore it to avoid the risk of serious problems in the future. Prevention is always a better option than a repair before the damage gets serious. You must always consider the maintenance routine.