How to Fix a Chainsaw Bar and Chain That’s Not Getting Oil


As a chainsaw cuts, it releases an incredibly high amount of energy, and a large amount of that energy is converted into heat. To help alleviate some of that heat build-up, chainsaws have built-in systems to dispense oil to the bar and chain while it cuts, greatly reducing friction and thus the conversion of energy to heat. However, if the bar stops getting oil, that heat can build up and cause all sorts of nasty problems, including burning the wood itself. If this is the situation you find yourself in, have no fear. In this article, we will discuss all the possible causes of your oil deficiency.

There are a few key problems that could be preventing oil from reaching the chain. These problems include a lack of oil in the reservoir, a debris blockage in the dispenser system, or a broken oil pump component. Because these issues vary in their severity and ease of repair, we will discuss them in order of least to most severe.

You Ran Out of Bar Oil in the Reservoir

Okay, I don’t want to insult you. I’m sure most of you checked this first, and you guys who have can move on to issue #2, but to those newbies for whom lightbulbs are turning on, keep reading.

A chainsaw requires regular fill-ups of bar and chain oil. In most cases, bar oil should be refilled every time the gas is filled, as they tend to deplete at a similar pace. If you find your bar running dry, the first thing you should check is whether you have any bar oil remaining in the reservoir. If you don’t, the fix is simple: put more oil in! Once it is filled back up, your bar should be getting oiled normally, but be sure to check the chain tension, as it is likely heat differentials from being run dry either loosened or tightened the chain.

There is a Debris Obstruction in the Oiling System

Occasionally saw dust can get in the system and clog one of the various conduits the oil needs to flow through. This is one of the most common reasons for a bar and chain not getting oil, and it is fairly simple to fix. It just can be a bit tedious to find the obstruction and clean it out. There are three primary areas that are likely to be obstructed: The oil holes on the bar, the oil dispenser near the clutch on the outside of the chainsaw, and the oil intake inside the reservoir.

Obstructions on the bar

Obstructions in the bar are common and easy to fix. On each side of the bar, there is a small hole that, when installed on the chainsaw, presses against the rubber gasket of the oil dispenser. A picture of this hole can be seen in the photo below.

An obstructed oil hole on the bar can prevent oil from getting to the bar and chain.

If this hole gets clogged with saw dust, it can prevent proper lubrication, so give it a visual inspection to see if there is any obstruction. If so, simply take a nail or pick and scrape out any debris. If you can see it, but the debris is rather impacted and isn’t coming our easily, you can also flip the bar around. The bar should have oil holes on either side, so it can be installed on either side.

It’s also a good idea to clear out the groove around the bar using the spark plug wrench, as this can often get obstructed too, although rarely does such an obstruction cause a system-wide lubrication failure.

Obstructions on the Oil Dispenser

Near the clutch, there is a rubber gasket that is usually pressed up against the aforementioned hole on the bar. This is where oil is dispensed to the outside and pumped into the bar. You can see this gasket in the photo below.

The gasket located by the clutch helps get oil to the bar and chain.

Visually inspect this port to ensure there is no debris clogging it and preventing lubrication. You can clean it out easily using your spark plug wrench.

The Oil Intake

This one can be a difficult obstruction to clear, as it is inside the chainsaw. However, hope is not lost. If you suspect there is an obstruction that originates from the inside, use a shop vac or other source of suction to try to get it out. Simply put the vacuum up to the oil cap and create a seal around it with a trash bag, glove, or your hands. This should force the oil in the pump system to move in reverse and clear whatever obstruction is blocking the system. Once it is out, try to knock it out of the tank.

In the future, try to prevent saw dust and debris from getting in the tank when you refill.

A Broken Oil Pump Component

If nothing so far has fixed the issue, it is likely there is an issue with the oil pump system itself, so replacement parts will likely be necessary, but that doesn’t mean it’s a tough repair. Luckily, the most common piece to break is also the easiest to replace.

Broken Worm Gear

The oil pump is actuated by a “worm gear” that looks like a plastic thread component. This little piece (as seen in the photo below) is located on the crankshaft behind the clutch and sprocket.

A broken worm gear can prevent the oil pump from turning, thus preventing oil from hitting the bar and chain.

Typically (for some unfathomable reason), these little components are made of plastic, and they can melt if they get too hot, or the threads can become damage if something happens to cause it to become “cross-threaded” in the normal functioning of the saw. These gears commonly become damaged, and if they do, the entire oiling system of your saw can become compromised.

However, with the worm gear removed, ensure the oil pump inside is spinning freely, as it is possible the problem originated in the oil pump and led to a damaged worm gear.

Damaged Fuel Pump

If the worm gear is undamaged or the gear of the oil pump is not turning freely, the problem is likely damage to the oil pump itself, and this component will likely need to be replaced.

A good way to test the functionality of the oil pump is to manually turn the gear actuated by the worm gear and examine the gasket that pumps oil into the bar to see if any oil seems to be moving. If nothing is happening, the fuel pump is likely broken.

Luckily, these components are not expensive, but it can take a bit of no-how to do the repair yourself. It is best to bring the saw into a qualified dealer or repair shop to have them replace the pump for you.

One of These Solutions Should Fix the Issue

The oil system of a chainsaw is prone to a lot of error, as there is a lot of opportunity for debris to enter the system or hear to damage components, but it is luckily a fairly simple system with a limited number of components. If you have been having trouble with your bar and chain not getting oil, reviewing these potential causes should help you diagnose the problem and find a solution.

On the bright side, my experience has been that having an issue with the oiler once helps you understand the system intimately, so you can have a better understanding of your saw and how to prevent issues and better diagnose them when they occur. Cutting wood, like anything, is a learning experience, and every repair teaches you a little more.

Zachary Lowry

A forester from northern Maine, I spent my early career working for large timberland owners, managing forest land and investments in the form of managing timber harvest operations as well as planning and managing precommercial thinning, planting, and herbicide application programs. These days I work on my own land and help timberland owners large and small manage theirs.

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