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non ferrous flake in oil screen

L

leaker311

Active Member
I was hoping someone could help point me in the right direction.

During annual I pulled the oil screen and found one 0.315 x 0.157 very thin shard of non magnetic piece of material. it almost looked like a thin sliver of aluminum. Interestingly I cant find anything in the filter although the oil that was left in the oil screen seemed grayish like there is aluminum "dust" mixed in the oil, maybe it is other contaminant (lead deposit?)

Have not send the oil in for analysis yet. The hartzell C/S prop was recently overhauled (5hrs ago) and the engine is running great and is 144hrs old.

Engine is an mattituck M1b IO-360.

Anyone seen this before? what can cause one lone sliver of silver non magnetic material in the oil screen? Can it come from the prop? What is the next best step? teardown?

Thank you so much for your time, any advice is appreciated.

Marco
RV-7
Punta Gorda, FL
 
I occasionally see a "speck" of metal in the finger screen. I have shown and discussed with several A&P's in the area......nothing to worry about and not that uncommon. Just continue to monitor screen on annual and cut oil filters at oil change. I've been told when an engine starts "making metal," you will definitely see far more than this.

Of course, you could always call your engine manufacturer for "official advice." Definitely would not "tear down" due to one metal flake.
 
It could be from a wrist pin plug or from the newly overhauled prop. I would not get too excited about this yet. Keep checking the pick up screen and filter media each oil change as usual.

Most piston wrist pin plugs are aluminum and ride directly against the cylinder bore. It is very much normal to see some small aluminum shavings/particles in the oil filter media from time to time. The "grayish" oil that was drained from the pick up screen plug was most likely caused from lead deposits that settled in the bottom of the sump. If you have not seen the lead paste deposits inside of an engine before it can be an eye opening experiance, but normal for an engine that burns 100LL. It may also be possible that the "snout" of the crankshaft wore some aluminum off of the I.D. of the prop hub when the propeller was reinstalled?
 
Thank you

I talked to both Hartzell and the shop that opened and resealed the hub, both were adamant that the hub/propeller cannot be the culprit.

I might have scored the Hub during install, I was careful and meticulous during the job but no way of knowing for sure unless I take it back off the crankshaft and actually inspect the hub.

Otherwise my next best guess is possibly the piston pin plugs based partly on this thread and Mahlon's input.
http://www.vansairforce.com/community/showthread.php?t=117603&highlight=Alum+flakes&page=9

My plan is to:
- check the oil cooler for additional flakes
- do a compression check to see if the cylinders are still in good shape
and go from there. I am wondering though if I should continue running the engine or do I risk scoring the cylinders if the pin plugs are indeed the cause?

Thank you regarding the lead deposits in the oil, makes a lot of sense and I do only run 100LL.
 
There is always a risk of doing further damage if indeed something is wrong.

That said, on the first oil change I did on my purchased flying RV-6A, I found a similar sized non-ferrous shard in the suction screen. The advice from multiple mechanics was to look for secondary symptoms (do your compression check) but lacking any, cut the oil change time in half and re-check. 200 hours and several regular oil change intervals later, no issues. YMMV.
 
If it were mine, I wouldn't be thinking of a tear down just yet - but I think I'd invest in finding out precisely what the metal is - that would give a lot of info (as well as possible peace of mind).

Piston pin plugs - no big deal but the cylinders have to come off (the larger questions is why). Something wearing in the case - not so good (but better fixed sooner than later). Bearings - hope it ain't so. Etc., etc. But, without knowing what the metal really is, it's just so much guesswork.

Consider a Google search for "SEM Analysis" for aircraft engines to find a lab.

Dan
 
DanBaier said:
If it were mine, I wouldn't be thinking of a tear down just yet - but I think I'd invest in finding out precisely what the metal is - that would give a lot of info.

Dan
Click to expand...

After spending $135 at AvLab to find out what I had in my filter I was told AMS4160 brass. A call to Lycoming materials lab and I was told there is no Brass of any alloy anywhere in the engine that could end up in the filter. Just fuel injection nozzles and fuel drains.
A tear down and what I found was a loose idler shaft generating aluminum, and worn ex guides. So, Id think twice before spending any money having the metal identified.
I was told if your engine is less than 12 years old, the materials lab will help identify it. So that may be a better play for you if it applies.
Tim Andres
 
Metal

I've seen this before , in an HIO-360 , thought is was the piston pins as it had a top overhaul within 250 hours . The jugs were pulled and all was fine . Cases split and it was the main bearings , pieces of them were flaking off . Not sure the cause , but they were shot .
 
well the plot thickens

I will try to have the flake evaluated to see what it is. It looks like aluminum, but uncertain until it is actually analyzed.

Rinsed the oil cooler and found one tiny sliver of aluminum little less than 1/32th x 1/16

I took a closer look at the filter and did the wash and rinse and see what comes out technique.

i found this:
http://i288.photobucket.com/albums/ll165/co_vd_b/photo_zpsa8xlqr0d.jpg

Certainly ferrous but no real pieces, it just seems like it is metal dust and just fades into a grey streak when gently rubbing it. I know the lycoming books say anything less than 1/2 a teaspoon just fly for 10hrs and recheck. I am far from anything close than a teaspoon but still....

The engine is fairly young (144hrs) can metal dust be part of the breaking in process?
 
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