Moisture on dip stick

[Vlakvark]

Good day folks

I have notice some moisture on the oil dip stick when I check the oil. Any ideas on how I can prevent that. The plane fly about 1-2 flights a week and is in a heated hanger with the temp turn down to 15C(60F). 

Thanks

J

[RobertGary1]

Should be fine. When you fly it do you fly for a full hour?

-Robert

[Vlakvark]

Ya. Usually 1.2hrs. Would that not contribute to corrosion? 

[rbridges]

You're going to have some moisture as a byproduct of combustion. 

[Pritch]

One thing that I have started to do is, after shutdown I open the oil cap and let the steam escape and leave it open until I get it in the hangar.  Once in the hangar I replace the cap, before closing the doors.  Not sure if it helps but it can't hurt.

Pritch

 

[MyNameIsNobody]

4 minutes ago, Pritch said:

One thing that I have started to do is, after shutdown I open the oil cap and let the steam escape and leave it open until I get it in the hangar.  Once in the hangar I replace the cap, before closing the doors.  Not sure if it helps but it can't hurt.

Pritch

 

Just hope you always pre-flight and check oil.  A human might forget sometime and have a dipstick not tight.  I think you are overthinking the moisture thing.  If you are flying 2x/week and changing the oil on a regular basis...

[Cruiser]

As air becomes saturated with too much humidity, it cannot hold the water vapor. Moisture is in the air all around us. When warm, moist air contacts a cooler surface, such as dipstick, it cannot hold as much water vapor so it condenses onto the cool surface.

This could be as simple at the hot air in the engine condensing so opening the oil dipstick to vent the engine might help.

If the moisture source is outside the engine, better circulation in the hangar, reduce the humidity level. 

[Vlakvark]

Thanks. No moisture in the hangar. 

[Cruiser]

Then watch the dew point temperature. 

Remember the old saying ...... when the temperature and dew point are within 2°F fog or low clouds may result. The same thing happens in your engine. If the dew point is near the temperature of the hangar, you will get condensation. 

[ArtVandelay]

One thing that I have started to do is, after shutdown I open the oil cap and let the steam escape and leave it open until I get it in the hangar.  Once in the hangar I replace the cap, before closing the doors.  Not sure if it helps but it can't hurt.
Pritch
 

I do this, but leave it off until the water vapor stops, I usually take this time to post flight, clean off parts of the plane, etc

[Vlakvark]

I will do that and see how it goes!!!

[pirate]

3 hours ago, Pritch said:

One thing that I have started to do is, after shutdown I open the oil cap and let the steam escape and leave it open until I get it in the hangar.  Once in the hangar I replace the cap, before closing the doors.  Not sure if it helps but it can't hurt.

Pritch

 

 

I agree. I've been doing this for the past 15 years, I just leave my dip stick partially off and leave the hangar. 

[Pritch]

3 hours ago, Cruiser said:

Then watch the dew point temperature. 

Remember the old saying ...... when the temperature and dew point are within 2°F fog or low clouds may result. The same thing happens in your engine. If the dew point is near the temperature of the hangar, you will get condensation. 

I do live in one of the foggiest places on the west coast, that why the Redwood trees are able to grow so tall, as they get a good portion of their water from fog.  KACV was developed during WWII to learn how to disperse fog.  Leaving the oil door open while venting the steam which only takes the time to push the plane into the hangar is enough and then put the oil cap back on and close ALL doors.

Pritch

 

[carusoam]

When opening the cap after flight to vent moisture...

Consider a two step method to avoid forgetting to put it back.  The O has an oil access door, if left open, it is a visual sign that something wasn't finished.  Being on the checklist is the second chance to make sure it doesn't get forgotten.

Remember, the dipstick cap is extra hot after flying...

Best regards,

-a-

Edited February 4, 2017 by carusoam

[Cyril Gibb]

I keep my dipstick unscrewed in the hangar.  The problem is cooling and resultant condensation.  No matter what we do, the relative humidity increases beyond the saturation point as the trapped moisture (regardeless of cap on or off) cools.  I've wondered if using a pump for 15 minutes to blow or suck through the oil filler would replace the moist combustion air with relatively dry outside air, reducing condensation and maybe corrosion. 

[carusoam]

Cyril, 

consider the engine dryer for this situation...

It is a fish tank air pump, a moisture adsorbing medium, plugs to keep air from entering the exhaust, and plumbing to connect it all together.  

Best regards,

-a-

[cctsurf]

I wonder if your engine oil is really getting hot enough in your flights...  1.2 hours should be enough, but if the oil temp doesn't get above about 180 (preferably higher, like 220), it won't evaporate off the moisture and it WILL contribute to corrosion.

Do you have an oil-air separator on the engine?  One of the downfalls to these is that they don't distinguish between fluids.  They will not easily allow the moisture to exit but instead return it to the engine.  Mike Busch advises against them...  I just try to make certain that I get the temp high enough to boil off the moisture.  I usually don't have the cool problem on my Mooney, it's usually too hot...  I do have this problem on my Cherokee.

[buddy]

I have an "o" and after every shutdown I unscrew the dipstick using a rag "it's hot" and leave the access door open along with leaving the rag on top of the cowling. The rag on the cowling and an open access door will remind you to screw the dipstick back in before the next flight. I have not seen any moisture in my oil cap or dipstick since.

[Cyril Gibb]

On 2017-02-04 at 11:45 AM, carusoam said:

Cyril, 

consider the engine dryer for this situation...

It is a fish tank air pump, a moisture adsorbing medium, plugs to keep air from entering the exhaust, and plumbing to connect it all together.  

Best regards,

-a-

Yup, I made one of those for when we're away from Gladys for more than a couple of weeks and we also install dessicant plugs.  

That would be a total pain to dry the desiccant often.  I was thinking more of an 80/20 solution that was quick and easy by just replacing hot & humid combustion byproduct air with outside air and not use dessicant.  A much higher volume pump than we need with our fish tank pump.  I know it wouldn't help with cylinder rusting, but it's the cam that I always worry about.

I'll build one when I get a few hours and test by blowing the exiting air against a cool surface to see if I can get a significant amount of condensation.

[DonMuncy]

49 minutes ago, Cyril Gibb said:

That would be a total pain to dry the desiccant often.  

In my dryer, I have to re-do the desiccant every three or four months. I don't find it to be a burden.

[neilpilot]

I fashioned a dryer when I parked my M20E in a hangar for 4 1/2 months.  That was April thru early July in Memphis; can you say "humidity"?

I found that even in the humid months the desiccant indicated less than half moisture breakthrough.  But I used a rather large reservoir of desiccant.

[Cyril Gibb]

Maybe I've got an air leak in my setup?  Obviously more experimentation needed.