Removing oil cap after flight.

This forum has been developed to discuss maintenance topics in Canada.

Moderators: ahramin, sky's the limit, sepia, Sulako, North Shore

Post Reply
Message
Author
User avatar
Rookie50
Rank (9)
Rank (9)
Posts: 1819
Joined: Mon Apr 09, 2012 6:00 am
Location: Clear of the Active.

Removing oil cap after flight.

#1 Post by Rookie50 » Tue Apr 19, 2016 7:14 pm

.....read this (couple places) if done immediately for 15-30 minutes may allow boiled off water to escape as steam. Reduction in sitting corrosion.

True or false?
---------- ADS -----------
  

Prodriver
Rank 4
Rank 4
Posts: 224
Joined: Tue Sep 17, 2013 9:42 pm

Re: Removing oil cap after flight.

#2 Post by Prodriver » Tue Apr 19, 2016 10:34 pm

That is why there is a breather and you get belly oil on your plane. The engine vents over board.
---------- ADS -----------
  
"I need a time machine"

Chris M
Rank 5
Rank 5
Posts: 321
Joined: Thu Aug 22, 2013 8:41 am
Location: Toronto

Re: Removing oil cap after flight.

#3 Post by Chris M » Wed Apr 20, 2016 3:47 am

Per Mike Busch (I'm paraphrasing): Not a bad idea. Anything that helps that moisture escape is good for the engine.

I usually pop it open after a flight while I refuel and tie down. Just make sure you don't leave the plane like that.
---------- ADS -----------
  

photofly
Top Poster
Top Poster
Posts: 6542
Joined: Tue Jan 18, 2011 4:47 pm
Location: Part of the "me, me, me" crowd, and loving every second of it.

Re: Removing oil cap after flight.

#4 Post by photofly » Wed Apr 20, 2016 4:23 am

Some enterprising person could invent a thing that twists onto the oil filler and gently blows in dessicated air, exhausting via the breather.

EDIT: like this: http://www.aircraftspruce.com/catalog/e ... gsaver.php

I suspect this and opening the oil filler will remove some of the water vapour from the engine voids and prevent condensation but without data I'd guess the water dissolved in the oil would have too long an equilibrium time with the air surrounding it for 20 mins with the cap off to do much good there.
---------- ADS -----------
  
Last edited by photofly on Wed Apr 20, 2016 5:47 am, edited 2 times in total.
“This isn’t flying, it’s falling. With style.”

Broken Slinky
Rank 4
Rank 4
Posts: 238
Joined: Fri Feb 21, 2014 10:47 am

Re: Removing oil cap after flight.

#5 Post by Broken Slinky » Wed Apr 20, 2016 4:39 am

Chris M wrote:Just make sure you don't leave the plane like that.
I leave a piece of paper towel or something hanging out of the oil fill door as a reminder the cap is off. Seen guys put something on the yoke to remind them too.
---------- ADS -----------
  

digits_
Rank (9)
Rank (9)
Posts: 1401
Joined: Mon Feb 14, 2011 2:26 am

Re: Removing oil cap after flight.

#6 Post by digits_ » Wed Apr 20, 2016 10:09 am

Broken Slinky wrote:
Chris M wrote:Just make sure you don't leave the plane like that.
I leave a piece of paper towel or something hanging out of the oil fill door as a reminder the cap is off. Seen guys put something on the yoke to remind them too.
Isn't the chance of damage to the engine due to dust/dirt particles entering the oil/engine while doing this bigger than the possible gains you could get from having some moisture exit the system ?
---------- ADS -----------
  

photofly
Top Poster
Top Poster
Posts: 6542
Joined: Tue Jan 18, 2011 4:47 pm
Location: Part of the "me, me, me" crowd, and loving every second of it.

Re: Removing oil cap after flight.

#7 Post by photofly » Wed Apr 20, 2016 11:05 am

Seeing as some engines run for decades with chunks of metal turning up in the oil filter I don't think a tiny bit of lint will do much. Just don't push a whole rag inside and leave it there :-)
---------- ADS -----------
  
“This isn’t flying, it’s falling. With style.”

User avatar
Rookie50
Rank (9)
Rank (9)
Posts: 1819
Joined: Mon Apr 09, 2012 6:00 am
Location: Clear of the Active.

Re: Removing oil cap after flight.

#8 Post by Rookie50 » Wed Apr 20, 2016 11:43 am

digits_ wrote:
Broken Slinky wrote:
Chris M wrote:Just make sure you don't leave the plane like that.
I leave a piece of paper towel or something hanging out of the oil fill door as a reminder the cap is off. Seen guys put something on the yoke to remind them too.
Isn't the chance of damage to the engine due to dust/dirt particles entering the oil/engine while doing this bigger than the possible gains you could get from having some moisture exit the system ?
I'm not sure I'd do it outside. Only in my hangar.
---------- ADS -----------
  

crazyaviator
Rank 7
Rank 7
Posts: 671
Joined: Sun Oct 21, 2007 7:52 pm
Location: Ontario

Re: Removing oil cap after flight.

#9 Post by crazyaviator » Wed Apr 20, 2016 12:00 pm

ASAS item is a good idea but in Canada we need to remember to block off the hole in the breather above the exit
---------- ADS -----------
  

digits_
Rank (9)
Rank (9)
Posts: 1401
Joined: Mon Feb 14, 2011 2:26 am

Re: Removing oil cap after flight.

#10 Post by digits_ » Wed Apr 20, 2016 2:08 pm

photofly wrote:Seeing as some engines run for decades with chunks of metal turning up in the oil filter I don't think a tiny bit of lint will do much. Just don't push a whole rag inside and leave it there :-)
Probably, but will the small amount of moisture in the oil do more or less bad stuff to the engine ?
---------- ADS -----------
  

Broken Slinky
Rank 4
Rank 4
Posts: 238
Joined: Fri Feb 21, 2014 10:47 am

Re: Removing oil cap after flight.

#11 Post by Broken Slinky » Wed Apr 20, 2016 7:12 pm

digits_ wrote:
Broken Slinky wrote:
Chris M wrote:Just make sure you don't leave the plane like that.
I leave a piece of paper towel or something hanging out of the oil fill door as a reminder the cap is off. Seen guys put something on the yoke to remind them too.
Isn't the chance of damage to the engine due to dust/dirt particles entering the oil/engine while doing this bigger than the possible gains you could get from having some moisture exit the system ?
I wrap the paper towel around the stick to allow it to vent and block some of the possibility of dirt. I also put the cowl plugs in. Haven't seen any weird spikes on the oil analysis to say excessive dirt is getting in.
---------- ADS -----------
  

Therewewere
Rank 1
Rank 1
Posts: 27
Joined: Wed Mar 18, 2009 3:57 pm

Re: Removing oil cap after flight.

#12 Post by Therewewere » Sun Oct 09, 2016 8:46 pm

The possibility of inadvertently leaving the cap off negates any positive results from the minuscule amount of moisture. Besides don't you think that the engine manufacture has taken this into account?

A very experienced AME once told me never leave anything undone that can be done up. Its just a recipe for disaster.

In over 23,000 hrs of flying, this is one of the dumbest "Myths" that I have ever heard of.
---------- ADS -----------
  

User avatar
5x5
Rank (9)
Rank (9)
Posts: 1381
Joined: Sun Feb 15, 2004 7:30 pm

Re: Removing oil cap after flight.

#13 Post by 5x5 » Mon Oct 10, 2016 12:55 pm

+1 for Therewewere. Risk vs reward simply doesn't compute favourably. Sometimes what seems to make "common sense", just doesn't.
---------- ADS -----------
  
Being stupid around airplanes is a capital offence and nature is a hanging judge!

“It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so.”
Mark Twain

cgzro
Rank (9)
Rank (9)
Posts: 1735
Joined: Wed Jul 25, 2007 7:45 am

Re: Removing oil cap after flight.

#14 Post by cgzro » Mon Oct 10, 2016 1:28 pm

[quote]That is why there is a breather and you get belly oil on your plane. The engine vents over board. [/quote]

The breather is not there to vent water vapour, its there to vent combustion blow by gasses otherwise you'd blow out the oil seals as the crankcase pressure built up. Of course some water vapour does get vented but not much once the engine stops.

Its very common to leave the dipstick out in the homebuilt/acro crowds but I've never been very convinced as to how useful it is. I think it would be more useful to remove the dipstick and then put air through the breather to force an exchange of air in the crankcase but if the air you put in is humid you may not be doing much good. An exchange of dry air through the engine is probably not a bad idea though.

However by far the BEST thing is to fly a lot ;) ... and drain and replace the oil regularly.
---------- ADS -----------
  

Zaibatsu
Rank 5
Rank 5
Posts: 312
Joined: Sat Sep 17, 2016 8:37 am

Re: Removing oil cap after flight.

#15 Post by Zaibatsu » Mon Oct 10, 2016 2:44 pm

5x5 wrote:+1 for Therewewere. Risk vs reward simply doesn't compute favourably. Sometimes what seems to make "common sense", just doesn't.
+2. Fly your plane often, and you don't have to worry about moisture. You've already got a breather tube.
---------- ADS -----------
  

Heliian
Rank (9)
Rank (9)
Posts: 1217
Joined: Wed Apr 29, 2009 2:14 pm

Re: Removing oil cap after flight.

#16 Post by Heliian » Mon Oct 10, 2016 4:29 pm

This oil cap gets opened to check and add oil. That's it.

I would even suggest that you will draw more moisture in as it cools.
---------- ADS -----------
  

cgzro
Rank (9)
Rank (9)
Posts: 1735
Joined: Wed Jul 25, 2007 7:45 am

Re: Removing oil cap after flight.

#17 Post by cgzro » Mon Oct 10, 2016 8:19 pm

Or blow helium into the case, displace oxygen around the lifters etc. Wonder how quickly it would leak out..
---------- ADS -----------
  

photofly
Top Poster
Top Poster
Posts: 6542
Joined: Tue Jan 18, 2011 4:47 pm
Location: Part of the "me, me, me" crowd, and loving every second of it.

Re: Removing oil cap after flight.

#18 Post by photofly » Mon Oct 10, 2016 8:46 pm

Nitrogen is about 100th the price and just as good.
---------- ADS -----------
  
“This isn’t flying, it’s falling. With style.”

User avatar
PilotDAR
Rank 10
Rank 10
Posts: 2594
Joined: Sun Sep 30, 2012 6:46 pm
Location: Near CNJ4 Orillia, Ontario

Re: Removing oil cap after flight.

#19 Post by PilotDAR » Mon Oct 10, 2016 9:25 pm

Nitrogen is about 100th the price and just as good.[as helium]]
... and won't cause a weight and balance change either! :lol:

I agree with just fly the plane often, or, preserving oil and desiccant plugs.
---------- ADS -----------
  

jetmechgm
Rank 0
Rank 0
Posts: 2
Joined: Fri Nov 04, 2016 6:14 am

Re: Removing oil cap after flight.

#20 Post by jetmechgm » Fri Nov 04, 2016 6:20 am

I find it difficult to imagine that in the age of human factors and all we have seen on this matter. Poor habits and practices as this exist.
Shame on the the AME that knowingly creates a chance for a inflight engine failure, I can not imagine that would be defined in an MPM or MCM and would create personal liability if an event occurred.
---------- ADS -----------
  

Post Reply

Return to “Maintenance”