checking Lycoming oil level? (plus a neat trick for adding oil)

[AJ88V]

Do you check your oil level just by pulling out the dipstick?  

Or do you pull the stick, wipe it and then check it again?  And if you do the latter, do you screw in the dipstick and then unscrew to check?  

I figure there's half a quart of difference in the level (typically no big deal, since these engines carry about double the oil actually needed to run without damage).

Oddly, I could not find anything definitive if you should check the oil with the stick screwed down, or without screwing it in. Not in my POH, not in the Lycoming docs, not on AOPA.  I always check screwed in.  You?

 

Now for the neat trick.  Found this on YouTube.  He says it doesn't build up 'vacuum', but he means pressure in the crankcase while pouring in oil.

 

[bigmo]

I guess there’s a video for everything. I don’t think of the oil dipstick as a gauge. It’s a rough estimate with far too many variables to yield an exact measurement. I personally use my 6 mark as my ‘ok’ mark. Below I add a quart, above I fly. 

Personally I always wipe the dipstick, insert but not screw in. Check.

For grins years ago, I did a check and then drained the oil, let it drain overnight, then measured what came out. Lots of room for error with my bucket, the presumed 1/2 quart trapped in the filter, oil film left in the bucket etc.. My end result was 6 on the stick was actually just shy of 7 quarts. So that’s one of the reasons I don’t overthink it.

As for the video - seems a good way to bugger up the threads…but if it works it works. Never experienced difficulties pouring oil into a funnel.

I DO however agree most people over tighten the dipstick. Barely finger tight on my a/c. It does seem to tighten on its own. I’ve had to grab my Gerber on a number of occasions on student’s a/c…so there’s definitely a lot of folks hulking that thing closed.

[EricJ]

If the idea of "breaking the seal" is so that it can ventilate, the breather tube should do that anyway.    If somebody has an air-oil separator that is clogged up or something, that might make a difference, but if it makes a difference it's more a sign that something is wrong somewhere else.   I just put the dipstick on the wing walk on the rage that I use to wipe it, so it's hard to miss if I forget it, and it's out of the way and won't make a mess.    Whatever works for people, though.

 

[MikeOH]

I unscrew and lift the dipstick until I can read the level, and screw it back in.  The level is always clear, so I see no reason to wipe with a rag or remove the dipstick. No muss, fuss, or mess

[Hank]

20 minutes ago, MikeOH said:

I unscrew and lift the dipstick until I can read the level, and screw it back in.  The level is always clear, so I see no reason to wipe with a rag or remove the dipstick. No muss, fuss, or mess

Me, too. 

If I need to add oil, I pull the dipstick up until I can fit the funnel beside it. Almost never take it out, unlike automotive use, because I never check the oil immediately after shutdown like at a gas station--it's a preflight activity, usually on a cold engine.

[Utah20Gflyer]

I measure from the screwed in position.   I don’t wipe before measuring because the oil is already level in the crank case and doing so only wastes oil. 
 

My tip for the day is when I remove the dipstick to add oil I pull it out partially and lodge it against the cowling door to hold the dipstick out of the oil.  I then continue my preflight and come back 5 minutes later and the dipstick is completely free from oil which means I don’t have to wipe it off.

When I screw down the dipstick I run it to the end of the threads but don’t torque it into place at all,  I’ve never had the dipstick back off or had any issues with doing it this way.  Before I learned better I’d screw it hand tight and often had a great bit of difficulty getting it off during the next pre flight.  

[M20F]

I was watching this TickTock the other day on walking.  It was pretty fascinating in that it involved putting your right foot in front of your left foot and repeating.  I was pretty thankful for this because I managed to get to the bar and pour myself another Tito’s rocks.  My wife really likes it because now I don’t have to scream for her to bring me a drink anymore.  
 

Honestly I am not certain which method of getting a drink I will use long term.  It is really great though to have an option.   I mean without this TickTock where would I be?

[Pinecone]

I carry one of the aux handles to loosen Lycoming dipsticks.  Most people over tighten them.

https://www.sportys.com/dipstick-removal-tool.html?srsltid=AfmBOor0mNxEo06Gh9uWfYMHuUxjFnKVxr-sonrkvtyLfNlVCLMUYbjf

 

[EricJ]

3 hours ago, Pinecone said:

I carry one of the aux handles to loosen Lycoming dipsticks.  Most people over tighten them.

https://www.sportys.com/dipstick-removal-tool.html?srsltid=AfmBOor0mNxEo06Gh9uWfYMHuUxjFnKVxr-sonrkvtyLfNlVCLMUYbjf

 

Does the same tool fit on the fuel selector for the folks who have trouble with that?

The Arrow I used to rent had a pair of pliers in the baggage just for this, as people would routinely overtighten that.   That's a big advantage to owning your own airplane. 

[redbaron1982]

4 hours ago, Pinecone said:

I carry one of the aux handles to loosen Lycoming dipsticks.  Most people over tighten them.

https://www.sportys.com/dipstick-removal-tool.html?srsltid=AfmBOor0mNxEo06Gh9uWfYMHuUxjFnKVxr-sonrkvtyLfNlVCLMUYbjf

 

Lycoming filler neck removal tool should be called! My experience is that if the dipstick is too tight, you will also unscrew the filler neck when removing it.

[Pinecone]

I thought the filler neck was supposed to be safety wired

[Andy95W]

1 hour ago, Pinecone said:

I thought the filler neck was supposed to be safety wired

It is.  The filler neck is just plastic, so if you crank down the safety wire it’ll break off the ear with the safety wire hole.  So the tube will loosen 1/4” and get stopped by the safety wire- which then causes more wear to the ear.

So the best thing is for people to simply not over tighten the dipstick.  There’s no reason to do so, it won’t come out in flight, and even if it did the oil still couldn’t get out.

[Pinecone]

I have no issues removing the oil dipstick on my Lycoming powered CAP-10.  But I don't over tighten it.

I do occasionally fly rental or CAP aircraft with Lycomings, and they are typically over tightened.

[FlyingDude]

When I need to add 1qt or less oil, I lift the dipstick out of the tube and hold it upright with just its tip entering the hole [no references being made to humans], and pour the oil along the dipstick using its adhesive property on the metal. If you hover the tip in the hole without touching the sides, you can pour lots. It's quick,  no frills, no mess, and you zip up the cowl door and go on your way. The method isn't very effective on windy days, but I don't like using a funnel on ramps.

This was the method we were taught at driving school to add fluids to acid batteries (with a glass rod). I guess now they teach kids to not drink that fluid.

[Fly Boomer]

33 minutes ago, FlyingDude said:

I guess now they teach kids to not drink that fluid.

Nah, they won't get any minerals, but it won't hurt them--it's just distilled water.

[Paul Thomas]

Here is my trick to adding oil. I always seem to have empty water bottles at the hangar and in the airplane when travelling. If I need to add oil, I cut a bottle in half to use as a funnel so that I don't have to keep an oily funnel in the airplane/hangar.

[FlyingDude]

2 hours ago, Fly Boomer said:

Nah, they won't get any minerals, but it won't hurt them--it's just distilled water.

The method I mentioned was intended for adding sulphuric acid. Water is just poured in.

[EricJ]

3 hours ago, Paul Thomas said:

Here is my trick to adding oil. I always seem to have empty water bottles at the hangar and in the airplane when travelling. If I need to add oil, I cut a bottle in half to use as a funnel so that I don't have to keep an oily funnel in the airplane/hangar.

Most water/soda bottles have cap threads that are compatible with the dipstick tube and will thread in just fine.     The "funnel" I keep in the hatch in my airplane is just the top cut off of an old water bottle with a shop towel in it to keep things reasonably clean.   It threads into the dipstick tube so even being somewhat small it's very stable in there.

[MikeOH]

This is what I use.  Keep it and a couple of quarts of oil in a plastic tray in the hat rack.