Weird looking oil

455 Bravo Uniform

455 Bravo Uniform

Final Approach
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455 Bravo Uniform
This is the post-flight drip from the breather tube. Oil has 6 hrs on it, and the drip has looked like this on the ground the last few flights. May have been like this before but may not have noticed due to the darkness of the old oil (plane is new to me and just starting to notice details).

Is this coloring and “froth” normal? Any internet experience or opinions?

B8E44EBA-4F68-4A52-A600-AA321826D390.jpeg 68825C94-DE37-4F69-9253-BDA04DECE32D.jpeg
 
That's just water/oil emulsion. Water vapor is a byproduct of combustion, and there's always a bit that leaks past the rings with all the other stuff that blackens the oil, and it condenses in the crankcase. The oil pump stirs it in with the oil as the oil circulates and forms that latte-looking stuff. Sometimes you see it on the dipstick, but most often the worst of it drips out the breather, since the breather tube is dumping blowby gases overboard, and the water vapor is condensing in the breather tube and mixing with misted oil there.

Short flights can do that, and colder weather will do it. If that stuff stays in the crankcase it causes corrosion. Longer flights and oil cooler/cowling blocking plates help to get the oil temp up far enough to evaporate the water off faster than it forms in the case.

Don't just ground-run the engine, either, in the mistaken belief that you're doing the engine some good. All you're doing is adding more water and causing more corrosion.
 
It's like deja vu all over again
 
Wrong thread whoops
 
Thanks @Dan Thomas

Lol, you guys are bored, go fly.

I started to pop the oil filler cap after each flight after the last oil change. Lots of vapor escapes (probably some fuel and water vapor. I figured it can’t hurt).
 
First time I saw that my heart skipped a beat or 3. It always happens when my reiff is plugged in and the cowling cover is on


Sent from my iPhone using Tapatalk
 
:D Maybe it’s the oil brand and weight, plus the snake oil additive I use.
 
Did you fly IFR?
It happens to me all the time after flights through rain / clouds
 
We see the ‘frothy drip’, what about the rest of the details? How does the oil look on the dipstick? What are the years and hours since overhaul? How are the compressions?

You could always start an oil analysis program with Blackstone or whoever else does it. Oil does get ‘frothy’ during and after a flight. Then you have ground contaminants mixing in. I wouldn’t get worked up over the frothy drip, I’d include all the other details that indicate overall engine health.
 
My C150 & my current 172 both did & do that. Every flight, some more than others, but it looks exactly like that. My oil on the checker-stick looks nice & clean for the moment.
 
sourdough44 said:
We see the ‘frothy drip’, what about the rest of the details? How does the oil look on the dipstick? What are the years and hours since overhaul? How are the compressions?

You could always start an oil analysis program with Blackstone or whoever else does it. Oil does get ‘frothy’ during and after a flight. Then you have ground contaminants mixing in. I wouldn’t get worked up over the frothy drip, I’d include all the other details that indicate overall engine health.
Click to expand...

Yes, oil on the stick looks good. About 150 since OH, 2 years ago or so. Compressions are good. Scoped cyl looked good. Oil analysis showed high chrome (there’s one my threads buried in here somewhere about that).
 
My oil doesn't get frothy, but it looks like Satan's split pea soup after 50 hours. So greenish. :eek:

(Phillips X/C 20W-50)
 
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