Understanding Chainsaw Bar Oil Leaks: Causes and Solutions

Are oil leaks from your chainsaw bar causing you concern? With our comprehensive understanding of chainsaw mechanics, we can help you identify the causes and their solutions. We have the answers to your chainsaw issues.

Loose fasteners, damaged lines, and overfilling cause leaks. Fix by opening caps to equalize pressure, replacing missing parts, not overfilling, inspecting & replacing damaged lines, adjusting oil flow, and keeping outlets clear. Regular maintenance helps prevent leaks.

Say Goodbye to Chainsaw Leaks: Oil leaks from your chainsaw bar are no longer a mystery. Dive deeper into our article to discover the causes and their solutions.

Why does my Chainsaw Leak Bar Oil when not in Use?

If a chainsaw leaks oil when turned off, the chances are that the oil tank might be overfilled or poorly ventilated. The pressure buildup within the tank causes some oil to flow out of the tank. Punctures in the oil lines could also cause oil to leak when the chainsaw is not in use.

A chainsaw that spills oil is never a good indication. It will make a mess and may degrade the chainsaw’s performance. You may need to put oil in your chainsaw regularly. Let’s look at some of the most prevalent reasons why a chainsaw could leak bar oil when unused.

● Reason 1 Chainsaw Leak Bar Oil: Poorly Vented Oil Tank

It is one of the least sought-after causes that could result in oil leakage. Chainsaw oil tanks should be ventilated to avoid the formation of a vacuum. Furthermore, the air pressure between the tank and the atmosphere should be equalized.

Most tanks include a one-way valve that enables air to flow into the tank to keep the air pressure constant. When the temperature varies substantially, the air pressure inside the tank fluctuates. For example, the tank’s air pressure drops at night due to a temperature reduction.

This allows air to enter the tank and equalize the pressure. During the day, as the temperature rises, so does the air pressure. Because the valve is just one way, air cannot flow out of the tank; hence, the only way to balance the pressure is to drip some oil from the ports.

This phenomenon is more prevalent in areas that encounter significant temperature changes.

– Fix:

Fixing this issue is relatively easy. To adjust the air pressure inside the tank, loosen the oil reservoir’s cap by a small amount. No oil would be forced to flow out of the ports now that the pressure has been equalized.

Tighten the cap on your oil tank after you’ve made this change. This simple technique is recommended whenever you start your chainsaw on a hot day after letting it sit all night.

● Reason 2 Chainsaw Leak Bar Oil: Missing Stud

In most chainsaws, a stud is visible from the muffler’s side at the bottom of the oil tank. There will likely be leakage if the stud is missing from its position. It is relatively small (approximately 0.1 inches in diameter) and is likely to become misplaced.

To check for this, use a flashlight to look from the muffler’s side and see if you can notice the stud or if a hole is apparent.

– Fix:

To acquire the stud from a local dealer, you must know its part number. Look through the owner’s manual to see if you can find the part number. If not, a similar-sized stud can be found at any hardware store. Just ensure the item has the same diameter as the hole and isn’t too long.

● Reason 3 Chainsaw Leak Bar Oil: Overfilled Oil

Many chainsaw users say overfilled oil is the most frequently reported cause of over-oiling. When the oil tank is overfilled, there is always the chance of oil seeping into the sprocket and chain, giving the appearance of a leak.

This is quite common in environments with considerable temperature changes. When the temperature suddenly rises, the already overfilled oil may expand and seep into sections of the sprocket and guide bar assembly.

This phenomenon of overfilling also applies to engine oil and fuel. Seepage is probable if the tank’s oil-fuel mixture (premix) is overfilled.

– Fix:

Ensure you haven’t overfilled the bar oil reservoir or the fuel tank with an oil mixture. Even if it were overfilled, the chainsaw would have expelled the extra oil, and it should not leak any more oil.

● Reason 4 Chainsaw Leak Bar Oil: Oil line leak

The oil line transports the bar oil from the tank to the pump. The tube may be punctured, causing some oil to spill from it. Tilt your chainsaw and remove the lower cover to see if the line is faulty. If there is a significant amount of oil buildup in that area, it is most likely due to a ruptured oil line.

– Fix:

Before reinstating the oil line, ensure the oil reservoir has emptied. To access the line, unscrew the engine mounting nuts and bolts (if applicable). Use a flathead screwdriver to pry it out of the holes. Replace it with a new oil line and reconnect everything that was removed.

Why does Oil Leak from my Stihl Chainsaw?

A chainsaw could leak oil if the oil tank isn’t correctly ventilated or the stud that secures the port is misplaced. Another possible cause of the problem is an overfilled tank. Most of the time, a considerable amount of oil beside a chainsaw doesn’t result from a leak. It’s commonly seen in the form of a residue.

Most new users become alarmed when they notice substantial oil around their Stihl chainsaw. Based on my experience with Stihl chainsaws, I can guarantee that seeing this oil spread is relatively standard. It is typical for a new chainsaw to leave oil behind, especially after cutting.

– Oil Droplets: Accumulation and Potential Leakage

Most new Stihl chainsaws spray a tiny mist of bar and chain oil off the chain onto the guide bar. When these droplets accumulate, they run down the guide bar, raising the possibility of an oil leak.

Furthermore, the clutch, the groove in the bar, and the sprocket all expel oil droplets that collect while cutting. This function is not a leak but rather oil flung from the chain as it passes around the guide bar.

I recommend storing your chainsaw on dry cardboard whenever possible to keep this oil from making a mess. Oil leaks are distinguished by a continuous flow of oil across your equipment.

Furthermore, in the event of a leak, you may frequently replenish the oil in your reservoir. When determining a leak, you should use the troubleshooting methods outlined in this article.

● Identifying an Oil Leak:

Store your chainsaw in a dry spot for a few hours to assess whether the oil puddles result from a leak or a normal throw-off from the chainsaw. Ensure it’s clean of any oil residues before storing it, and take note of the oil level in the tank.

If you notice a drop in the oil level in the tank after some time, as well as puddles of oil around the device, it’s a sure sign of a leak.  This is one of the common causes of a chainsaw oil leak.

An alternate strategy can be used to save time. Place a piece of paper in front of your chainsaw and run it for a few minutes with the guide bar directly above the paper—tiny oil droplets on the paper result from regular oil throw-off from the chain. However, if the paper becomes drenched with oil, it becomes a problem.

– Recognizing Increased Oil Consumption as a Sign of a Leak

One tank of bar oil is typically used for every tank of fuel. However, if there is a leak, the oil consumption increases. You may need to inject oil more than once or per gasoline unit. This is because some oil is flung from the chain as it passes around the guide bar at high speed.

This is a normal function of the chainsaw and not a sign of a problem. However, if the oil continuously flows out, it is likely in the form of a leak.

Remember, it’s essential to identify the difference between oil flung from the chain as it passes around the guide bar and oil leaking from the chainsaw. The former is a normal function of the chainsaw, while the latter indicates a problem that needs to be addressed.

● Adjusting the Oiler:

If the leak point hasn’t been identified and the oil leakage is considerable, the oiler mechanism needs adjustment. The oil adjustment knob is located beneath the chainsaw, and the adjustment screw controls the oil flow to the oil pump.

Most chainsaws feature a notation on the screw (represented by a plus and minus sign) that tells us which way the screw must be turned.

Turning the screw in a plus direction increases the oil flow, and turning it in the minus direction does the opposite. In most cases, the oiler is set to the max setting, so the oil consumption increases dramatically and indicates possible leakage.

How do I Stop my Chainsaw from Leaking Bar Oil?

Ensure the oil lines aren’t punctured to stop your chainsaw oil from leaking. Avoid overfilling your oil tank, and always keep it thoroughly vented. Make sure the oil outlets aren’t plugged with sawdust.

Once you’ve checked that the oil puddles aren’t due to regular operation and the oiler setting is set correctly, your chainsaw is probably leaking oil. There can be more than one reason behind this. Let’s develop an effective strategy to counter these and prevent oil leakage from your chainsaw.

● Stop a Chainsaw Oil from Leaking 1: Refurbish the Oil Lines

Your oil delivery mechanism may have encountered a fault. The oiler mechanism consists of the oil reservoir connected to an oil pump.

The pump connected to the throttle delivers the oil to the outlets via an oil line. In case of a leak, check if the oil line is ruptured. Also, examine the pump and tank connections. Check and replace the seals at the connections if they seem worn out.

● Stop a Chainsaw Oil from Leaking 2: Avoid Overfilling

Overfilling your tank often causes additional oil to drip off the guide bar and imitate a leak. To prevent this, ensure your tank isn’t filled and the oil level is about half an inch short of the brim.

Also, ensure that the tank is vented, preventing pressure buildup within, which could cause some oil to drip out, as explained in the above sections.

● Stop a Chainsaw Oil from Leaking 3: Keep the Outlets Clean

Oil outlets at the sprocket and the guide bar should be thoroughly cleaned. These outlets are prone to get clogged with sawdust after continuous use. Due to the blockage, the oil cannot flow out and exerts back pressure at the oil pump and the reservoir.

Consequently, it may tend to form a leakage from those points. Use a thin metal wire to dislodge debris and sawdust deposits to clean the outlets.

Do Electric Chainsaws Leak Oil?

An electric chainsaw may also leak oil despite its different technology from a gas chainsaw. The causes of oil leakages are the same as those discussed for gas-powered chainsaws.

The electric chainsaws may leak oil if they are overfilled. Hence, you need to siphon some oil to solve the issue. If the oil pump is dusty, the electric chain saw may leak oil even after you have extracted it from the reservoir.

Excessive oil on the oil pump gaskets might lead to leaks. Clean the gaskets and inspect them for wear. Replace the gaskets if they are ruptured.