Chainsaw issue

Depending on the saw the chain oiler works one of two ways.

Very low end saws (like the one I carry) may be "Drip oilers" suffice to say they leak, however you have already told me yours is not that type (It does not leak a drop at home)

Beter ones it's a engine driven (or gear driven or cam operated) pump. These should not leak but heat can cause pressure to build in the oil chamber, Likewise altitude changes induce pressure relative to atmospheric

And bouncing around can operate the pump.

Id' start with benting the cap to equalize pressures

I would also bucket the saw (set it in something where the leak does not make you as upset) when not sawing.

I set my saws on these Pig Mats

They come in handy for a lot of other things too.

I think it is the nature of the beast. I have a Poulan and a Stihl. They both mark their territory.

We get cat litter from Sam's in the rectangle shaped bucket. Buzz the bottom off that thing and it makes a good stand for the saw to sit on.

For extended storage or travel, I dump the oil reservoir back in the oil container.

lc0338 wrote:
Here is an answer from a Stihl saw FAQ:

Why does my saw leak bar oil?

The way our units lubricate a chain, most of the oil is distributed around the inside of the bar rails as it is circulated by the oil reservoirs in each drive link of the chain. The amount of oil being circulated inside the bar at any given time can be between .3 and .5 oz. As a general rule of physics, the oil will be pulled down by gravity once the chain stops turning, collecting at the bottom of the bar and seeping through the chain to puddle underneath the bar & chain assembly as well as under the drive sprocket. The fact that it appears to be continuing to seep after the unit is cut off for several days is owed to the viscosity of the oil and the anti-flinging compound (lithium) mixed with the oil at the refinery. These factors give the oil a very thick consistency, which in turn explains a slower flow rate. This condition is deemed to be normal for any chainsaw with a similar bar & chain lubricating system.

If the unit continues to seep oil after a few days, the problem may be the vacuum relief valve located in the side of the engine housing between the oil output hole and the bar stud(s). This valve has an internal spring and ball type arrangement with the ball pressed against the vent hole of the casing of the valve, when the tank develops a vacuum from the normal process of the oil being pumped out. The ball is pulled away from the hole, allowing air to enter into the tank and break the vacuum so that oil can continue to flow to the bar and chain assembly. Once the vacuum is relieved, the spring pushes the ball back against the hole of the valve casing. Sometimes debris may become trapped between the ball and the hole. This would cause the oil to keep "weeping" because there must be some measure of vacuum in the tank to keep the oil from flowing freely once the unit is shut down. More often than not, all one needs to do is to take a small pin or needle and push it into the hole of the valve (identifiable as a small silver disk with a small hole in the center) about 6 or 7 times to loosen the debris. This should re-seal the orifice and keep the oil from seeping from the output hole when the saw is stored.

Excelent advice and right on,,I have Stihl saw also and always clean the debris and dust of it after using it,just a comon sense,,never leaked oil anywhere..

Thanks lc0338.

I was on the right track, wrong description of the valve.

Here is an answer from a Stihl saw FAQ:

Why does my saw leak bar oil?

The way our units lubricate a chain, most of the oil is distributed around the inside of the bar rails as it is circulated by the oil reservoirs in each drive link of the chain. The amount of oil being circulated inside the bar at any given time can be between .3 and .5 oz. As a general rule of physics, the oil will be pulled down by gravity once the chain stops turning, collecting at the bottom of the bar and seeping through the chain to puddle underneath the bar & chain assembly as well as under the drive sprocket. The fact that it appears to be continuing to seep after the unit is cut off for several days is owed to the viscosity of the oil and the anti-flinging compound (lithium) mixed with the oil at the refinery. These factors give the oil a very thick consistency, which in turn explains a slower flow rate. This condition is deemed to be normal for any chainsaw with a similar bar & chain lubricating system.

If the unit continues to seep oil after a few days, the problem may be the vacuum relief valve located in the side of the engine housing between the oil output hole and the bar stud(s). This valve has an internal spring and ball type arrangement with the ball pressed against the vent hole of the casing of the valve, when the tank develops a vacuum from the normal process of the oil being pumped out. The ball is pulled away from the hole, allowing air to enter into the tank and break the vacuum so that oil can continue to flow to the bar and chain assembly. Once the vacuum is relieved, the spring pushes the ball back against the hole of the valve casing. Sometimes debris may become trapped between the ball and the hole. This would cause the oil to keep "weeping" because there must be some measure of vacuum in the tank to keep the oil from flowing freely once the unit is shut down. More often than not, all one needs to do is to take a small pin or needle and push it into the hole of the valve (identifiable as a small silver disk with a small hole in the center) about 6 or 7 times to loosen the debris. This should re-seal the orifice and keep the oil from seeping from the output hole when the saw is stored.

It's probably coming from the chain oiler. Here are a few tricks I've heard but might not work on all saws:

1) After use remove oil cap to relieve pressure then put cap back on
2) Lay chainsaw on side with oil cap facing up
3) hang chainsaw by bar
4) If these tips don't stop it like others place in pan to contain oil

Quite common irritation. Nothing to do with elevation. Most chainsaws have a check valve in the system which sticks open from the tiniest bit of sawdust or dirt that may have entered the oil reservoir when being refilled. The problem is even worse when some people switch to special "Summer oil", lighter weight chainsaw oil. Sthil chainsaws are especially noted for this.

Golden_HVAC wrote:
I was also going to say elevation changes will inflate the oil reservoir, then pump it onto the chain automatically as you go uphill.

Good luck,

Fred.

Mine does it sitting on a shelf at my home.. That shelf does not change "elevation"..

Typically temperature changes will cause the oil to expand/contract a bit. But in reality it is more likely leftover oil in the tubing past the oil pump that drains to the bar..

Then you also have residual bar oil on the chain and bar that gravity ultimately will bring to the bottom of the bar over time.

Like I mentioned before, I would be more concerned if no oil marks.. That would be a sign of a dry chain and bar and too little oil..

Now, if your oil tank is getting completely drained while stored I would be concerned that there is a leak in the tank, tubing or oil pump..

Put it in a heavy trash bag or cardboard box.