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Oil suction screen finding and question

YellowJacket RV9

Well Known Member
Patron
I am pretty good about pulling my oil suction screen, and in 6 years and > 500 hours of flying, I have never found anything at all on it. Yesterday, however, during my CI oil change, I did find one small flake of non-magnetic metal in the oil, stuck to the bottom of the retaining bolt for the suction screen, as pictured below, thin and about 3/32" long. Remainder of suction screen as well as oil filter element are pristine, as usual. Compressions are all >75/80. Borescope exam is on tap for tomorrow.


A few questions -

Since I've never found anything before, I'm embarrassed to admit I don't even know which way oil flows through the screen. I had thought oil flows from the outside in, and as such particles would be trapped on the outside of the screen. Am I mistaken?

Secondly, any recommendations on a lab to send this to for analysis? I am just starting my CI, so plane is obviously grounded until I have further information.

Lastly anybody care to share similar experience and findings?

Thanks

Chris
 

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Oil Direction

A few questions -

Since I've never found anything before, I'm embarrassed to admit I don't even know which way oil flows through the screen. I had thought oil flows from the outside in, and as such particles would be trapped on the outside of the screen. Am I mistaken?

Secondly, any recommendations on a lab to send this to for analysis? I am just starting my CI, so plane is obviously grounded until I have further information.

Lastly anybody care to share similar experience and findings?

Thanks

Chris[/QUOTE]

The oil travels from inside the screen to the outside. Ergo, debris will be trapped inside the screen.
 
Flake

Is it metal or carbon? Put it on something hard like a back rivet plate or bucking bar, tap with a small hammer and see if it crumbles. If it does I would presume it’s carbon and I would fly 10-20 hrs then check screen & filter again. If it doesn’t crumble I would call a oil analysis company as see if they can give you a opinion on where it could have come from.

Don Broussard
RV9 Rebuild in Progress
57 Pacer
 
Is it metal or carbon? Put it on something hard like a back rivet plate or bucking bar, tap with a small hammer and see if it crumbles. If it does I would presume it’s carbon and I would fly 10-20 hrs then check screen & filter again. If it doesn’t crumble I would call a oil analysis company as see if they can give you a opinion on where it could have come from.

Don Broussard
RV9 Rebuild in Progress
57 Pacer

Thanks Don - I tried to tap on it and it seems fairly hard. I will call Blackstone since I use them for oil analysis already.

Had a thought that since the last suction screen inspection I changed to a SureFly mag - I wonder if that metal could be from a drive gear cotter pin. It sure looks similar. Going to pull the SureFly tomorrow and check.

Chris
 
Had a thought that since the last suction screen inspection I changed to a SureFly mag - I wonder if that metal could be from a drive gear cotter pin. It sure looks similar. Going to pull the SureFly tomorrow and check.

Chris

Aren't cotter pins cad plated steel, therefore magnetic?
 
Looks too rough to be any critical part and most critical parts are magnetic. My guess would be a chuck of casting flash from the case broke off. I don't see how a chunk of aluminum or magnesium of that size, shape and texture can be from a critical part. It could have been floating around in the oil pan since engine assembly and just finally got sucked into the screen.
 
I agree

Looks too rough to be any critical part and most critical parts are magnetic. My guess would be a chuck of casting flash from the case broke off. I don't see how a chunk of aluminum or magnesium of that size, shape and texture can be from a critical part. It could have been floating around in the oil pan since engine assembly and just finally got sucked into the screen.

If you can't find a machined surface on the piece, I tend to agree it is probably casting flash. Thank God you have a suction screen, otherwise this would most likely have done serious damage to pump.
 
I am pretty good about pulling my oil suction screen, and in 6 years and > 500 hours of flying, I have never found anything at all on it. Yesterday, however, during my CI oil change, I did find one small flake of non-magnetic metal in the oil, stuck to the bottom of the retaining bolt for the suction screen, as pictured below, thin and about 3/32" long. Remainder of suction screen as well as oil filter element are pristine, as usual. Compressions are all >75/80. Borescope exam is on tap for tomorrow.


A few questions -

Since I've never found anything before, I'm embarrassed to admit I don't even know which way oil flows through the screen. I had thought oil flows from the outside in, and as such particles would be trapped on the outside of the screen. Am I mistaken?

Secondly, any recommendations on a lab to send this to for analysis? I am just starting my CI, so plane is obviously grounded until I have further information.

Lastly anybody care to share similar experience and findings?

Thanks

Chris

Have you called Lycoming Tech Support? I found a couple of slivers the first time that I pulled the screen after purchasing my -10 in 2018. Lycoming offered to analyze them at their lab, gratis, even though the engine was roughly 9 years old by then.
 
Thanks all for the input. I am cautiously optimistic that as mentioned, it is just a bit of casting or other debris that found it’s way to the sump, especially considering that oil analysis and filter inspection are spotless. I am going to send it off to a lab while I continue my inspection, but hopefully it’s just an anomaly and I can re-inspect after 10 hours or so of flight. It does emphasize the importance of that screen though.

The engine is an overhauled unit with a newer top end so I doubt Lycoming would help, but I am going to try AvLab.

Thanks

Chris
 
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