Oil in Spark Plug Well: What Are the Causes and Solutions?

Oil in spark plug well is a frustrating problem that is common in cars with various leaking points. You may notice this issue during routine maintenance or while checking for low oil levels.

Oil in Spark Plug Well

In any case, you must now have some questions since you’ve discovered them. This comprehensive guide provides answers to all your questions regarding oil in spark plugs, so read on!

What Are the Reasons for Oil in Your Spark Plug Well?

One of the main reasons for oil in your spark plug well is bad head gaskets. Other reasons are leaky ring seal, leaking valve and valve cover, faulty piston, and faulty piston compression rings. Once you’ve noticed oil on your spark plug well, you should check for why.

The symptoms of oil in spark plug well are engine misfire, low fuel economy, blue-colored exhaust smoke, and lots more. You can easily detect the presence of oil on your spark plug by simple observation. This is helpful while seeking to resolve any problems that develop quickly.

These are some of the most common evidence of oil in spark plugs:

  • Reduced fuel economy: Any decline in combustion efficiency, including that induced by spark plug pollution, might result in greater fuel usage.If you’ve noticed greater pump pain, spark plug fouling could be the fault.
  • Engine failure: Oil-contaminated spark plugs are less likely to provide ignition. This usually manifests as a misfire on one or more cylinders.
  • Backfiring: In severe circumstances, oil-tainted spark plugs can cause an engine to backfire. This is due to less-than-ideal combustion efficiency.
  • Blue-colored exhaust smoke: Burning oil produces blue smoke, which is much easier to notice than white smoke and associated problems. In most situations, this kind of exhaust indicates oil pollution in at least one combustion chamber.

Here are some of the most common reasons for oil in your spark plug well.

– Leaking O-ring Seal

Your spark plugs may not have a gasket, but they use O-rings. These O-rings keep oil and other contaminants on one side of the spark plug and dry on the other. You may have a leaky spark plug O-ring seal with only oil on one spark plug. It is one of the most popular reasons for oil on your car’s spark plug well. As a result, you must solve the issues as soon as possible. A leaky O-ring seal might cause your engine to misfire, resulting in more severe damage.

– Bad Head Gasket

While most people associate a blown head gasket with coolant in the compression chamber, it could also cause an oil leak. It is common for oil to enter the combustion chamber when this occurs. You’ll notice a lot of smoke, oil in your coolant reservoir and oil on the tips of your spark plugs.

Before the situation worsens and leads to more serious issues, you must replace the head gasket. However, the good news is that head gaskets are inexpensive, and the bad news is that replacing them is often time-consuming.

– Leaking Valve Guides

Valve guides always keep your intake and exhaust valves in the proper position. They also include seals that prevent oil out of the combustion chamber. If those seals fail, oil enters the combustion chamber and is only a hop, skip, and jump away from getting on the spark plug gaskets.

Reasons of Oil in Spark Plug Well

A valve guide, like other components here, are relatively inexpensive but require significant effort and time to replace. This might result in a hefty charge at the repair shop.

– Leaking Gasket Cover

Valve cover gaskets in your car keep oil toward the components that require it and away from those that do not. The spark plugs are one of the components it keeps oil away.

However, oil can easily flow into the spark plugs if the valve covers gasket leaks. Valve cover gaskets, like head gaskets, are inexpensive, but replacing them is time-consuming.

– Faulty Piston Compression Rings

Compression rings surround each piston in your engine, preventing oil from entering the combustion chamber. However, when these rings are destroyed, nothing prevents oil from entering the combustion chamber.

These rings keep things functioning smoothly and prevent more significant issues. As a result, if you suspect damaged compression rings, you should repair them as soon as possible.

– Faulty Piston

While damaged or cracked pistons are uncommon, they are not unheard of. Combustion chambers grow incredibly hot, which can become too much for pistons as they age. A damaged piston necessitates an engine rebuild, which is costly.

If you ignore the problem, you risk the car breaking down on the roadside and potentially damaging your engine. Pistons that are cracked or broken should be addressed.

How Can You Remedy Oil in Spark Plug Well?

You can remedy oil in spark plug well by removing the car’s valve cover and inspecting the head gasket, taking off the spark plugs, inserting a new set of plugs, replacing the valve cover gasket, and placing the spark plug gasket back.

Take note that you can drive with wet spark plugs, but this is never recommended. First and foremost, when a spark plug is saturated with oil, it loses its capacity to arc correctly. This, in turn, frequently results in a visible misfire issue.

Furthermore, if the source of the oil contamination is not addressed, such spark-related concerns will deteriorate with time. These are some of the step-by-step remedies for dealing with oil on spark plug wells:

– Remove the Valve Cover and Inspect the Head Gasket

The head gasket is an elastic band that seals a relatively small area of the engine. To inspect the head gasket, use a screwdriver to remove the valve cover. After that, you should be able to see the spark plugs and tubing. Seals and gaskets will also be seen.

Check for cracks and other damage. If a check reveals that the source of the oil on the spark plug threads is the head gasket, it must be replaced immediately.

– Take off the Spark Plugs

The valve cover protects the spark plugs. To replace these, you must first remove the valve cover. Remove the spark plug tubes and set them aside before proceeding. After that, using pliers that can easily free them, remove the clamps from the hoses that lead to the valve cover. The hose can then be removed using your hands.

Fixes of Oil in Spark Plug Well

Then, remove the electrical harness from the valve cover’s top. After that, you can use a large socket and a power handle to remove the valve cover nuts. Remove the nuts one by one using the tools unless you can easily pry them away with your hands.

Now, take the screwdriver and pry beneath the valve cover, which is frequently stuck on. It is easily removed with a bit of wiggling and prying. After removing the valve cover, the seals in each spark plug can be removed.

– Don’t Clean the Plugs

One key point that many automobile owners need to pay attention to is to not be tempted to clean and reuse old plugs because they may still have some oil on them that you can’t see. Because the spark plugs are already faulty, replacing them with new sets is better, which will not cost you a fortune.

Take note that you can’t reuse spark plugs for your car. While some people use cooking oil decontaminating a discarded spark plug using a hand-held propane torch, this may not be the ideal course of action. While these methods work, they are better for motorcycles or lawnmowers than vehicles.

Spark plugs are reasonably priced and frequently come pre-gapped, saving time and effort during installation. As a result, you don’t have to utilize any form of the old, marginalized spark plug.

Before installing new gaskets and seals, clean the head and valve cover. Cleaning these parts removes old particles, allowing the new parts you’re installing to seal better. When cleaning, use the proper greaser and only plastic equipment to avoid damaging the cylinder head or valve cover.

– Replace the Valve Cover Gasket

It is essential to obtain the gasket in the shape of the component. Furthermore, before purchasing a gasket for a vehicle, one should inspect the substance and quality of the gasket. The high-quality silicone material is likely helpful for the durability of the car and the valve cover gasket. Furthermore, these do not require frequent retyping, which lowers work and time expenses.

Replacing Car Valve Cover Gasket

So, after you have it, apply a liquid called sealer to the edges to prevent the new gasket from slipping over. Furthermore, the gasket placed over the liquid sealer will tightly hold its position, preventing oil from entering the spark plug.

– Place the Spark Plug Gasket

Finally, install the spark plug gasket on the rim of the spark plug well. These are circular and installed like the valve cover gasket with liquid sealant. Once finished, bolt the nuts previously removed in the order 2-3-1-4 to avoid damaging the valve cover.


– Is the Oil in Your Spark Plug Well Going To Burn Off?

Yes, the oil in your spark plug well is going to burn off. However, it depends on whether the oil source is rectified or unknown. If the underlying source of this oil pooling is addressed, the oil found within a vehicle’s spark plug well will burn off.

However, if the oil source is not discovered and corrected, fresh oil will simply pool in place much faster than “burn-off” can occur. This will result in massive shambles. If the source of any oil-pooling has been adequately addressed, any leftover oil will be burned up in a reasonable amount of time. The time required for this operation is mainly determined by the quantity of drivetime accumulated at operating temperature.

– How Can You Clean Oil off Your Spark Plug Well?

You can clean oil off your spark plug well by using a towel. Tuck a shop towel into the spark plug well using an extension or similar extended instrument. This shop towel should be in place for 10 to 20 minutes, allowing it to absorb most of the oil.

While there are several methods, this is the most effective. Before attempting to soak up leftover impurities, a small amount of brake cleaner or carburetor cleaning can be used to thin down any problematic oil.

Solving Oil in Spark Plug Well

Will Using Amsoil or Redline Motor Oil Help Prevent Oil in Spark Plug Well?

Using the amsoil vs redline motor oil comparison, let’s address the question of whether these oils can prevent oil in spark plug wells. Both Amsoil and Redline motor oils are high-quality synthetic oils known for their performance. While they can provide excellent protection and cleanliness to your engine, preventing oil in spark plug wells depends on various factors like gasket integrity and proper maintenance. Regularly inspecting and replacing faulty gaskets and seals is crucial to prevent such issues.


Oil in spark plug can be dangerous for you and your vehicle. Let’s discuss some of

the essential points made in the article.

  • The reasons for oil in your spark plug well include a bad head gasket, leaky ring seal, leaking valve and valve cover, faulty piston, etc.
  • The symptoms of oil on spark plug wells are engine misfire, low fuel economy, blue-colored exhaust smoke, and lots more.
  • To deal with oil in spark plug wells, remove the valve cover, inspect the gasket head, remove the spark plugs, replace the valve cover, and place the spark plug gasket.
  • You can clean a spark plug of oil by using a towel as an extension. The towel should be in place for up to 20 minutes to soak as much oil as possible.
  • It is not ideal to reuse spark plugs for your car. They may be faulty and predispose you to unhealthy driving conditions or even accidents.

Once you notice signs of oil being present in your spark plug well, check the underlying problem and solve it as soon as possible.

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