Chainsaw Leaking Bar Oil When Sitting

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Are you a chainsaw user who has been noticing bar oil leakage in your chainsaw and don’t know why? If yes, then this is definitely the best place for you to be.

Chainsaw leaking bar oil when sitting is a common problem that most chainsaw users go through. Your chainsaw could be leaking oil due to reasons like a poorly vented oil tank, an overfilled oil tank, a missing stud from the oil tank, a ruptured oil tank, and more. Moreover, the oiler’s adjustment screw could be set too high as well, which might give you an impression of an oil leak. A chainsaw leaking bar oil when sitting could be not a huge problem, but you still need to get it fixed as soon as you can. 

In this article, you will get to know all about chainsaw leakage, why is chainsaw leaking bar oil when sitting, how to stop the chainsaw from leaking oil, and more. Continue reading to get all the answers that you are looking for.

Chainsaw Leakage Can Be a Major Issue

Have you purchased a chainsaw but noticed that your chainsaw is leaking bar oil when it is sitting and not being used? Don’t worry, this is quite common and can be fixed easily.

A chainsaw needs timely lubrication of the bar and chain as a part of its regular maintenance. It is common for a chainsaw to leave oil stains at the place where it is being stored. However, if you notice that the oil is leaking at a considerable amount and continues doing so over a prolonged period, it might be a cause for concern. 

You should remember that there is always a reason behind something like this, but it isn’t necessarily an alarming one. A chainsaw leaking bar oil when sitting idle can be a problem if you aren’t careful. Although measures need to be taken to stop the oil leakage from your chainsaw, the reasons are not that complicated. 

How is Oil Leakage Different From Normal Throw-Off

One of the most important components of running a chainsaw is a chainsaw bar and chain oil. It is used to lubricate the chainsaw saw bar and chain. When the saw is cutting, it’ll experience huge friction as it is passing through the wood and cutting it. 

Aside from lubricating oil, a chainsaw will require a special fuel that is a mixture of oil and gas. Both, the lubricating and fuel oil might leak. This is why you need to identify what is oil leakage and what is a normal throw-off.

Most of the time, chainsaw users are getting worried about things that aren’t actually problems at all. Therefore, you need to know what is normal and what is a problem. It is important to know how to differentiate between oil leakage and oil throw-off.

The easy way to differentiate the two would be to note the oil level in the tank. After that, check after a while if there are oil blots on the surface and oil level in the tank might also have decreased. This will be clear identification of leakage.

You have to clean your chainsaw properly such that there are no oil drops present on the chainsaw. This will make the results more accurate as well.

Why is the Chainsaw Leaking Bar Oil When Sitting?

If your chainsaw leaks oil when sitting idle, chances are that the oil tank may be overfilled or ventilated poorly. The pressure buildup in the tank can cause some oil to flow out of the tank. Punctures in the oil lines can also cause oil to leak when your chainsaw isn’t being used.

A chainsaw that spills oil isn’t a good indication at all. It won’t just make a mess, but it might also degrade the performance of your chainsaw. You might have to put oil in the chainsaw regularly. Here are some of the most common reasons why you are experiencing chainsaw leaking bar oil when sitting and not being used – 

1. Poorly vented oil tank

One of the most common issues that can result in oil leakage is a poorly vented oil tank. Chainsaw oil tanks need to be ventilated to avoid the formation of a vacuum. Moreover, the air pressure between the tank and the atmosphere needs to be equalized. Most tanks come with a one-way valve that allows the air to flow into the tank for keeping the air pressure constant. If the temperature substantially varies, the air pressure inside the oil tank will fluctuate.

For instance, the air pressure in the tank tends to drop at night, owing to a reduction in temperature. This will allow air to enter the tank and equalize the pressure. During the day, with the rise in temperature, the air pressure rises as well. As the valves are only one way, air cannot flow out of the tank as the only way of balancing the pressure will be to drip a few drops of oil from the ports. This phenomenon is seen more in areas that encounter significant temperature changes.

Resolving this issue is rather easy. For adjusting the air pressure inside the oil tank, you should loosen the cap of the oil reservoir by a small amount. No oil must be forced to flow out of the ports once the pressure has been equalized. You should tighten the cap of the oil tank once you have made this change. This simple technique is often recommended when you’re starting the chainsaw on a hot day after you have let it sit idle all night.

2. Missing stud

In most chainsaws, a stud will be visible from the muffler’s side at the bottom of your chainsaw’s oil tank. If the stud is missing from its position, there could be oil leakage. It is rather small (approximately 0.1 inches in diameter) and it could get misplaced. For checking this, you should use a flashlight and look from the muffler’s side to see if you can notice the stud or if there is a hole apparent.

For acquiring the stud from a local dealer, you’ll have to know its part number. You should look through the owner’s manual and see if you’re able to find the part number. If not, you can find a similar-sized stud at any hardware store. You should just ensure that the new item has the same diameter as the hole, and it isn’t too long.

3: Overfilled oil

According to many users, overfilled oil is commonly reported because of over-oiling the chainsaw. If the oil tank is overfilled, there’s always a chance of oil seeping into the sprocket and chain, which ultimately leads to oil leakage. This is pretty common in environments that have considerable temperature changes. If the temperature rises suddenly, the already overfilled oil might expand and seep into sections of the sprocket and guide bar.

Overfilling also occurs for engine oil and fuel. If the tank’s oil-fuel mixture (also referred to as premix) is overfilled, so there will be a decent probability of seepage.

You should make sure that you have not overfilled the bar oil reservoir or the fuel tank with the oil mixture. Even if it was overfilled, the extra oil would be expelled by the chainsaw, and it shouldn’t leak any more oil.

4. Oil line leak

The oil line in a chainsaw is responsible for transporting the bar oil from the oil tank to the oil pump. The tube might be punctured, which causes some oil to spill out from it. You need to tilt the chainsaw over and then remove the lower cover for seeing if the line is faulty. If there happens to be a significant amount of oil buildup in this area, it is likely because of a ruptured oil line.

Before you reinstall the oil line, you should make sure that the oil reservoir has been emptied. For obtaining access to the line, you should unscrew the engine mounting nuts and bolts. You need to make use of a flathead screwdriver for prying it out of the holes. Then, replace it with a new oil line so that you can reconnect everything that was removed.

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Why Do Stihl Chainsaws Leak?

If the oil tank in your chainsaw isn’t ventilated properly or the stud securing the port has been misplaced, a chainsaw might leak oil. Another possible reason for this issue is an overfilled tank. Most of the time, a large amount of oil beside a chainsaw is not the result of a leak.

If you notice a fair amount of oil around your Stihl chainsaw, you shouldn’t get alarmed. If you have experience dealing with Stihl chainsaws, you will know that oil experience is relatively common. It is typical for chainsaws to leave oil behind, especially after a session of cutting.

Most Stihl chainsaws, especially if they are new, spray a tiny mist of oil from the chain onto the guide bar. Once these drops accumulate, they can run down the guide bar, raising the possibility of an oil leak. Further, the clutch, the sprocket, and the groove in the bar can all expel oil drops that collect while cutting. You should keep in mind that this isn’t actually a leak.

For keeping the oil from making a mess, it is recommended that you should store your chainsaw on dry cardboard when possible. Oil leaks can be distinguished by a continuous flow of oil across your chainsaw. Further, in the event of a leak, you could replenish the oil in the oil reservoir. When you find a leak, you must proceed with the troubleshooting methods and resolve the problem.

Identify the oil leak

Store your Stihl chainsaw in a dry spot for a few hours for assessing whether oil puddles are due to a leak or a normal throw-off from the chainsaw. You should ensure that your chainsaw is clean of any oil residue before you store it, and take note of the oil level present in the tank. If you notice a drop in the oil level in the tank after a while as well as puddles of oil around your chainsaw, it is a sign of a leak.

An alternate strategy can be used for saving time. You should place a piece of paper in front of the chainsaw and run it for a couple of minutes with the guide bar directly above the paper. Look for the small oil drops on the paper that can be a result of regular oil throw-off from the chainsaw chain. If the paper becomes drenched with oil, it can become a problem.

One tank of bar oil will typically be used for every tank of fuel. However, if there is a leak, the oil consumption can go way up. You might have to inject oil multiple times per gasoline unit.

Adjust the oiler

If the oil leak hasn’t been identified and the leakage is considerable, the oil mechanism will require adjustment. The oil adjustment knob is located under the chainsaw, and the adjustment screw will control the oil flow to the oil pump.

Most chainsaws come with a notation on the screw that’ll tell you which way the screw needs to be turned. Turning the screw in the plus direction will increase the oil flow, while turning it in the minus direction will do the opposite. In most cases, the oiler is set at the maximum setting, due to which the oil consumption drastically increases, giving you an indication of a possible leak.

Do Electric Chainsaws Leak Oil Too?

It is obvious that gas-powered chainsaws use oil for running and are prone to leaking oil. But does this apply to electric chainsaws too? Despite using a different technology than a gas-powered chainsaw, an electric chainsaw can also leak oil. The causes of oil leakages are the same as you get on gas-powered chainsaws.

An electric chainsaw might leak oil if they get overfilled. Hence, you’ll need to siphon out the oil to solve this issue. If the oil pump is dusty, an electric chainsaw might continue leaking oil even after you have removed some of it from the reservoir. Excessive oil on the oil pump gaskets could lead to oil leaks. You should clean the gaskets and then inspect them for wear. Replace the gaskets in case they are ruptured.

Store a Chainsaw Properly to Avoid Oil Spills

Storing the chainsaw properly will help prolong its life and keep oil spills away. Chainsaws must always be drained of gas and oil before being stored and topped up before use. If you need to store your chainsaw with lubricant in the tank, you should lay it on its side with the oil cap facing up and slightly open.

Opening the cap slightly will allow air to escape while also preventing the pressure that can force oil onto the guide bar. If you do that, you shouldn’t forget to tighten the cap back up once again before using the chainsaw, or you might end up with a huge mess on your hands. Many chainsaw owners forget to do this, but this is a mistake that you will rarely make twice.

chainsaw and chainsaw oil

Storing a chainsaw with the guide bar slightly raised will be a great way of minimizing the mess caused by oil leaking. Raising the bar will give gravity more to work with, which will force the oil residue on the bar and chain to the lowest part of the chainsaw. It means that the oil residue will flow to the same place, which is good because it’ll make cleanup a lot easier.

If you are placing your chainsaw in the same position each time with a piece of paper or cardboard under it, you’ll soon notice the exact place where the oil is leaking from. After that, all you’ll need to do is place a small container in this spot when you are storing the chainsaw.


Is it normal for oil to leak from the chainsaw?

To an extent, chainsaws are supposed to leak oil. A few drops of oil are normal, as it’ll likely be the residue oil from the chain. However, if there is a huge puddle or if the oil isn’t coming from the chain, then something is definitely out of order, and you need to investigate further.

Why does my chainsaw drip a lot of oil from the bottom?

The oil you’re using in your chainsaw should be of a viscosity that adheres to the chainsaw chain without being too thin or too thick. If you have chosen the wrong oil for your chainsaw, it might be the reason why oil is dripping from the bottom. It is recommended that you shouldn’t use waste oil in your chainsaw so that you can avoid this situation.

How to stop my chainsaw from leaking oil?

You should not overfill the oil tank, as the oil might escape through the port if the reservoir is overfilled. Most chainsaws of a specific model come with a maximum fill line on the reservoir. Filling it until slightly below the line will be the safest option. You can keep your chainsaw free of oil leaks when using it and when you’re putting it away.

What causes sudden oil leaks?

The common causes of oil leaks in a chainsaw include a poorly vented oil tank, overfilled oil, and missing stud. Further, oil line leak can also cause chainsaw oil leaks.

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Hi, I'm Mike - but my friends call me Backyard Mike. I'm the founder of this website, and I'm addicted to outdoor power tools. I love to work with wood and share my knowledge here on this website with you. You can find more about me here.