Spark plugs are crucial components of every vehicle as they generate the spark that ignites the fuel and air mixture in the internal combustion chamber.
Spark plugs can tell a lot about the health of your vehicle’s engine. Finding oil on the spark plugs can indicate a fault with the ignition system. The plugs can also be carbon fouled, indicating a rich running condition.
A common observation during spark plug inspection is oil saturating an electrode tip. Oil plays a significant role in lubricating the engine’s components while operating.
If the components do not have enough oil, the engine will overheat because of the friction caused by moving components rubbing against each other.
However, oil pouring into the spark plug is also undesirable. It can cause issues with your engine’s functioning and performance. Oil leaking into the spark plug must be checked promptly to maintain car service.
What Does A Spark Plug Do?
The spark plugs are responsible for igniting the air and fuel mixture to create energy-generating combustion in your engine.
The combustion procedure requires strict precision from each component of the engine, including ignition at precise moments in time for optimal combustion.
The spark plugs ensure this by maintaining the right temperature in the engine’s combustion chamber. If the temperature in the combustion chamber is too low, the resulting spark might not be hot and strong enough, resulting in a loss of energy.
If the temperature is higher than what’s required, it can lead to what is called pre-ignition, which is an ignition that occurs too early and thus will not result in optimal combustion.
Needless to say, despite being a small component, faulty spark plugs heavily affect your engine performance, and oil on spark plug threads is a common issue that must not be ignored.
How Does Oil Get on Spark Plugs?
An important question you might ask is how oil gets on your spark plug. A likely explanation for why there might be oil on the spark plugs is because of an unbalanced mixture of oil.
Usually, the ratio is 50 parts gasoline and 1 part oil. The disruption in this ratio can cause spark plugs to be drenched in oil.
Faulty piston rings cause oil to seep through your spark plugs. You can visibly see the presence of oil on the sparkplug and any visible leaks. You can also check the oil layer below the second ring. This way, you can identify a leak from piston rings.
Can I Drive with Oil on My Spark Plugs?
Spark plugs that are significantly oil-contaminated can result in an engine misfire. Because a misfire can cause additional damage to other parts of the vehicle, such as the catalytic converter, it’s a good idea to address oily spark plugs right away.
Causes of Oil in Spark Plug
When your spark plug is in good condition, your car’s ignition should function normally, and you should have no issues.
But what if you find oil on the spark plugs bottom? This issue is caused by two separate systems:
- The spark plug system
- The lubrication system
Because the spark plug ignites energy in the combustion chamber, which contains the fuel/air mixture, both are beneficial to the engine. Oil, on the other hand, works well for the engine’s moving parts, reducing friction between them.
The oil is stored in the oil pan, which has a capacity of six litres. The oil is moved by the oil pump and makes its way down to the oil filter before reaching other parts.
The oil should not come into contact with the spark plug or enter the spark plug well, as this can lead to serious problems.
If this occurs, it is recommended that you search online for full car service near me and request that a car mechanic can fix the problem as soon as possible. The following are the five major reasons why oil is discovered in spark plug wells:
#1. Aged Valve Guide Seals.
The valve guides help with the intake of air into the car’s engine, and they secure the valves while doing so. The valve guide seals are effective, but they can wear out over time.
You will need to replace them at some point during your full car service near me because they prevent oil from reaching the spark plug well. If you don’t, you could have serious problems as oil shouldn’t get to the spark plugs.
#2. Worn Out Valve Cover Gasket.
When you look at your car’s engine, you’ll notice a metal cover on the engine known as the “valve cover.” This seal is designed to keep leaks from the vehicle’s engine at bay.
Nonetheless, there are gaskets between the valve cover and the engine, and they eventually fail. This type of failure becomes more pronounced as the engine temperature rises, and the valve cover gasket becomes brittle.
As a result, you may soon notice some leaks allowing oil into the spark plug well.
#3. Faulty O-Rings.
If you’ve ever handled spark plugs, you’ve probably noticed the O-ring seals beneath the spark plug tubes. These seals effectively serve as a cover for the spark plug well.
Nonetheless, they deteriorate over time, and if damaged, oil can leak into the spark plug well. As a result, immediate action is required to avoid further complications.
Please keep in mind that the current spark plug will need to be replaced as well because the oil will saturate it and render it unsuitable.
#4. Failed Piston Compression Rings.
Piston rings, which are located above and beneath the piston, keep oil from entering the combustion chambers of the car. These rings are also crucial in removing excess oil from the cylinder walls.
With worn-out piston compression rings, they can rarely prevent oil from flowing towards your spark plugs. The engine oil odour would be detectable throughout the cabin in this case. You’d notice blue exhaust from the car every day.
#5. Faulty Piston.
Aside from allowing engine oil to flow into the cylinder and saturate the spark plug due to a faulty piston ring, a bad piston can also cause oil to accumulate in the spark plug well.
As a result of the excessive heat, the piston may crack. While driving, a faulty piston can cause engine misfire, excessive oil combustion, and rattling noises.
You should not ignore such a problem and should resolve it as soon as possible to improve the performance of your engine.
Symptoms of Oil in Spark Plug
A few symptoms tell you there’s oil in the car’s spark plug well. At the sight of these common signs, you will promptly discover such an issue and fix it before the car develops further problems.
Recognizing these signs is crucial when to remove oil from the spark plug well. Some of the common symptoms of oil in spark plug wells include:
#1. Gas Smell from the Tailpipe.
Have you ever wondered why you keep smelling gas coming from the exhaust pipe of your car? This could indicate that there is oil in your Toyota Camry’s spark plug well. This is true for many other vehicles, and in some cases, the odour penetrates the car cabinet.
#2. Blue Smoke from the Exhaust.
The exhaust pipe may soon begin to emit blue smoke, indicating that oil is being burned somewhere in the engine. Typically, such indicators appear when there is oil in the spark plug well.
When there is oil on the spark plug, it affects the engine’s efficiency and how it burns fuel. The fuel supply increases as the ECU attempts to adjust the fuel ratio.
Regardless, unburned excess fuel in the combustion chamber would pass through the exhaust valve.
#3. Decreased Engine Performance.
As the oil in the spark plug well makes contact with the plug, spark generation is reduced. Remember that this spark is in charge of the car’s ignition. The oil contamination of the spark plug tip would be disastrous.
In essence, the fuel/air mixture would have fewer chances of igniting in the combustion chamber of the vehicle. There will be insufficient pressure for the engine to function properly if there is no proper combustion.
#4. Engine Misfiring.
Engine misfiring can occur in any of the engine’s cylinders due to incomplete fuel/air mixture combustion.
With oil in the spark plug well, the plug is less likely to generate enough spark to complete the ignition of the gas/air mixture. As a result, you will begin to notice misfiring in your vehicle’s engine.
#5. Increased Fuel Consumption.
An increase in fuel consumption indicates that the spark plug is being clogged by oil. In essence, if you notice an increase in fuel consumption, inspect the spark plug to see if it has any oil on it. This sign will show you how to drain the oil from the spark plug well.
#6. Engine Backfiring.
Often, engine backfiring occurs when the fuel/air mixture combusts outside the engine cylinder’s combustion chamber. You can notice this symptom when there is oil in the spark plug well.
It results from the improper combustion of the fuel particles, causing them to forcibly move to the exhaust.
Oil On Spark Plug Threads: Step-by-Step Remedy
The many components above can be responsible for oil leaking into spark plugs. So, to fix the issue of oil on spark plug threads, make sure you are equipped with the following tools:
- Valve cover gasket and O-ring spark plug tube seal
- Power Handle
- Spray cleaner (for oil)
- Pliers
- Socket and spark plug socket
- Ratchet and extension
- Engine sealer
- Screwdriver
Now, let’s, in turn, inspect each of the possible culprits below to find out exactly what causes oil to leak into the spark plugs.
First and foremost, you need to turn off your car and then proceed to disconnect your car battery terminals. This will ensure that the engine is off and not supplying power.
Remove the valve cover and inspect the head gasket
Being a very small part of the engine, the head gasket is an elastic band meant to seal. To inspect the head gasket, you must remove the valve cover with a screwdriver.
Once you have done that, you will be able to see the spark plugs and the tubes. The seals and gaskets will also be exposed. Inspect for any cracks or other damage.
If an inspection points to the head gasket as the culprit for oil on spark plug threads, you’ll need to replace it right away.
Remove the spark plugs
Spark plugs are built into the valve cover. Therefore, to replace them, you must remove the valve cover. Before this step, take out the spark plug tubes and put them on the side.
Once it is done, take the clamps off the hoses that go to the valve cover using pliers that can easily unlock them. Next, you can use your hands to remove the hose.
Then, remove the wiring harness on the top of the valve cover. Once accomplished, you can get a big socket and power handle to take the nuts out of the valve cover.
For this, make sure to remove the nuts one by one with the tools unless it is easy to pry them loose with your hands.
Now, get the screwdriver and pry under the valve cover as it is often stuck on. With a little wiggling and prying, one can easily get it off.
Now, after the valve cover is removed, the seals located in each of the spark plugs can be removed.
One important note that many car owners ignore: Do not be tempted to clean and use the old plugs again, as they might still have some oil left on them that you cannot see.
Since the spark plugs are already faulty, the best thing is to replace them with new sets, which won’t cost you a fortune anyway.
Clean the head and valve cover
Do note that you need to clean the head and valve cover before installing new gaskets and seals. Cleaning these parts helps remove old particles and thus helps the new parts you are installing to have a tighter seal.
When cleaning, make sure to use the right greaser and only use plastic equipment so that the cylinder head or valve cover does not get damaged in the process.
Install the new valve cover gasket
Getting the gasket as per the shape of the component is essential. Moreover, one must also check the material and the quality of the gasket before purchasing it for the vehicle.
Normally, the high-quality silicone material is considered good for the durability of the car and the valve cover gasket. Furthermore, these don’t need retyping often, which not only reduces the work but at the same time expenditure, too.
So, once you have it, first add a liquid called sa ealer at the edges so that the new gasket doesn’t slip over. In addition, the gasket placed over the liquid sealer will tightly secure its place, thus preventing the entrance of oil on the spark plug.
Install the spark plug gasket
Lastly, one needs to place the spark plug gasket on the rim of the spark plug well. These are circular and are placed in the same manner, using the liquid sealant as the valve cover gasket.
Once finished with it, bolt the nuts in the order 2-3-1-4 that were removed earlier to avoid any damage to the valve cover.
Contact Professionals
Not everyone knows how to use mechanic tools and how to fix issues with their vehicle’s engine. If you are one of those, there is no need to panic.
Instead of doing something wrong and creating more significant issues, getting your car checked by a professional is preferable. They have years of experience and know how to manage vehicle issues easily.
FAQs.
How can I tell where the oil leak is coming from?
Carefully inspect the area around the spark plugs, looking for signs of oil seepage. Check the valve cover gasket, spark plug tube seals, and the area around the cylinder head.
Can I fix oil on spark plug threads myself?
Yes, depending on the cause. Replacing a valve cover gasket or spark plug tube seal is a relatively straightforward DIY repair. However, if the problem is more serious, such as worn piston rings, it’s best to consult a mechanic.
Is it normal to have a little bit of oil on spark plugs?
A very small amount of oil residue might be normal, especially on older engines. However, if you see significant oil buildup or dripping, it’s a sign of a problem that needs attention.
Why is oil on spark plug threads a problem?
Oil can interfere with the spark plug’s ability to fire properly, leading to misfires, rough idling, reduced engine performance, and increased fuel consumption. In severe cases, it can even damage the spark plug or ignition system.
To wrap it up, the spark plug’s role is quite larger than its size in the functioning of the engine. Therefore, it’s the responsibility of the car owner to keep a check on the condition of the engine and determine that there is no oil on the spark plug threads.
Final Words
Spark plugs are essential for gasoline-operating vehicles, as they help in engine ignition. Thus, the spark plug must remain in good condition for the engine to run smoothly.
Issues with the spark plug would affect the engine adversely, and you may even notice the car starts but won’t stay running.
With oil in the spark plugs well, there would be less spark generation for ignition. Thus, it may seem crucial to clean the spark plug hole and replace the spark plugs and O-ring seals.
You can read through this piece to learn more about the causes, symptoms, and fixes for oil on the spark plug.