Chainsaw Leaks Bar Oil When Stored: Causes and Solutions

The chainsaw is a beautiful invention; a real triumph of human innovation and industry. 

I’d be willing to wager there’s nothing more satisfying than holding a finely tuned chainsaw firmly in both hands and hearing it growl as it slices through the thick trunk of a tree!

However, chainsaws, as you may have found, require regular maintenance to stay functional. Oil leakages, while not normal, are common.

In this article, we will:

  • Expand on some of the likely reasons as to why a Chainsaw Leaks Bar Oil When Stored
  • Offer helpful solutions to ensure that your chainsaw is back up and running in no time.

Let’s get started!

Chainsaw Leaks Bar Oil

How a Chainsaw Lubrication System Works

Tanks and Pumps

Chainsaw lubrication systems are generally quite simple. 

There is a tank that houses the bar oil, a vent to balance the interior and exterior air pressure, and a filter to trap unwelcome substances. 

In a lot of chainsaws, the air vent is a simple one-way valve. This tank is connected to an oil pump via a tube called the oil line.

The pump, which is powered by the crankshaft of the chainsaw, facilitates oil flow out of the tank and onto the chain and the guide bar through what is known as the outlet hole.

Chainsaw Bar Oil

Your chainsaw may require different types of bar and chain oil depending on the environment you’re using it in. 

There are generally two types of bar and chain oil; a thicker variety for warmer environments/climates, and a thinner one for colder environments/climates. This is due to the fact that oil thickens when it’s cold.

Why Does My Chainsaw Leak Bar Oil? Oil Leakage Causes & Solutions

Oil Leakage Causes

1. Poorly Vented Oil Tank

When bar oil is pumped out of the tank, the space it leaves is filled up by air. 

If the vent on your chainsaw’s tank isn’t functioning the way it should be, this could cause a vacuum which draws more oil out of the tank. 

This surplus oil has nowhere to go other than running off your chainsaw’s bar and therefore leaking out. if the vacuum is strong enough, eventually the tank could become damaged and more susceptible to leakages.

A simple way to fix this issue is by using pressurized air or even an aerosol such as WD-40 to unplug the vent. 

Another solution is to slightly loosen your chainsaw’s oil reservoir upon first starting it up to equalize the pressure. Ensure the cap is tightened again before using it!

2. Missing Stud

If your chainsaw is missing a stud, it is possible that oil will leak out of it via the empty hole the stud left behind.

Luckily, chainsaw studs are cheap and easy to replace. If possible, consult your chainsaw’s owner’s manual to find the exact specifications of your chainsaw’s studs. 

If not, you should be able to find the size of the stud your specific model of chainsaw takes with a bit of Googling!

3. Overfilled Oil Tank

Oil is much more likely to seep out of your chainsaw if the oil tank is overfilled. While not technically a leak, an excess of oil on the bar and chain can often give the appearance of one. 

In an environment where temperature regularly fluctuates, oil can also expand quickly – further forcing it out of the tank.

If this is the reason why your chainsaw seems to be leaking oil, the good news is that there is nothing wrong with it!

In order to maintain the oil tank at an appropriate fullness, it is recommended that you fill up before use – not after. This is to avoid any expansion of oil that may occur due to temperature changes while it is in storage.

4. Oil Line Leak

The oil line is the tube that carries the oil from the tank to the pump. If the oil line is damaged in any way, it is conceivable that oil will escape from any of these points. 

In order to check on the condition of your chainsaw’s oil line, you will most likely need to remove its lower cover. 

If there appears to be a build-up of oil on or around the oil line, there’s a good chance that it is damaged and will need replacing.

When replacing an oil line, the first thing you need to do is ensure the oil tank is empty. 

Next, to remove the damaged oil line, you will likely have to remove your chainsaw’s engine mounting nuts and bolts. However, different models will vary. Replace the old oil line with the new one and put the parts back the way they were.

IMPORTANT: Your best bet here will be finding a tutorial on how to do this that uses the same model you have (or at least a similar one)!

If you’re not sure how to go about doing this, don’t start dismantling your chainsaw blindly; you may cause more damage than there was to begin with. Instead, take your chainsaw to a registered dealer/repairer and ask them to do it for you.

How To Determine Where Your Chainsaw Is Leaking Oil From

Chainsaw Is Leaking Oil

Above are the four main places your chainsaw could potentially be leaking oil from. If you notice a pool of oil, check each of these sites.

If none of them seem to be the issue, it could be the case that your chainsaw is running smoothly and there is normal throw-off occurring as the chain rotates around the guide bar. 

This could be coming straight off your chainsaw or potentially being flung back onto its body, where oil residues may collect in grooves and recesses.

Final Thoughts

With any luck, this article will offer you the solution you need to service your chainsaw’s lubrication system and get it back up and running the way it should. 

If you’re still looking for answers, I highly recommend that you find out the make and model of your chainsaw and see what type of specific advice or help you can find for it. 

And remember: if you don’t feel comfortable doing something to your chainsaw, it’s best not to – seek professional help from a registered dealer/repairer!


Is It Normal for Chainsaws to Leak Oil?

While it is not supposed to happen, it is common for chainsaws to leak oil. There are a variety of reasons why a chainsaw may appear to be leaking oil, so don’t worry – there is most likely a straightforward solution.

What Position Should a Chainsaw Be Stored In?

To prevent oil leakage in storage, it is best to store your chainsaw empty on a flat surface and with the oil tank lid slightly ajar.

Your chainsaw should be stored in a secure, dry place, sheltered from any extreme temperatures (out of direct sunlight), and out of reach of children.

How Do I Know If My Chainsaw Is Leaking Too Much Oil?

It is common for a chainsaw to leak a little bit of oil. However, if your chainsaw is leaking puddles of oil on a regular basis, you should check its oil tank, oil line, and studs for any damage/missing pieces.