"Trace metal found" in recently overhauled engine logs

T

T Bird

Pre-takeoff checklist
Joined
Jul 24, 2021
Messages
117
Display Name
Display name:
T Bird
Looking at a plane with about 400 hours on the engine since overhaul in 2021. Flown regularly the whole time since the overhaul so no time sitting. In the last several engine log entries it notes "trace metal found in oil filter." I'm no expert but my understanding is any metal coming from an engine is a bad sign, but it really doesn't make sense that such a fresh engine flown regularly would have issues. Is this actually common/something to not be concerned about? If I decide to move forward I'd get an extensive prebuy of course but just curious what people think of this? I've looked at logs of plenty of other aircraft with relatively fresh engines and haven't seen comments like that in the logs before so that's why I ask.
 
T Bird said:
I'm no expert but my understanding is any metal coming from an engine is a bad sign, but it really doesn't make sense that such a fresh engine flown regularly would have issues.
Click to expand...
It depends more on how they define "trace metals." But in general most piston engines will have some minute metal particles in the filter at each oil change simply due to the nature of the engine. The key is the type, size, and amount of those particles. Perhaps review the OEMs recommendation on those particles to develop a base line. For example, here's Lycoming SB480 on the matter. As to the mx record entries, how they are written tend to be subjective to the person and should be viewed the same.
 
I’d say, any mention of metal after several oil changes past the engine breakin, iis cause for further investigation as Bell206 suggests. Amount, and composition will tell you a lot. Could be a piston pin cap, a spun bearing, a deteriorating cam lobe, rings, etc, etc.Go here and take a look.

The Savvy Aviator #44: Making Metal

Uh oh! You've discovered some ferrous metal in your oil filter, and the oil analysis lab reports a big spike in iron. Is it time to panic?
www.avweb.com www.avweb.com
 
Who did the overhaul? Big name shop or Bob the local A&P? 400 hours is low time. If plane and price are favorable then have pre buy inspect filter again along with suction screen. Consider engine mid time and roll the dice.

Help to know make and model too.
Also figure some people won’t think twice before buying if price is on point. You may lose the buy.
 
It's normal to find a few flakes in the oil filter. I've rarely cut open an oil filter that didn't have what I'd describe as a trace; maybe 2 or 3 small flakes or whiskers. I usually write "no abnormalities" to avoid this very situation. I'm not saying don't ask the question, but I wouldn't outright dismiss the airplane over this. Take a look at that SB Bell linked above...it takes a LOT of metal to condemn an engine. Way more than you'd think, and way more than I'd be comfortable flying behind.
 
Take a look at oil analysis also. As @Jim K noted above, a few minute flakes are not unusual but if you find pieces with part numbers then there is a concern ...
 
You can send Continental your AMS numbers for proper metal identification. I think Avlab are the only ones that offer AMS numbers. You can also send them your oil filter to pull these numbers. According to the SB that Bell provided, it appears that Lycoming offers a similar service.
 
No big deal, engine failure that's why you practice emergency landings and good lawyers are for.
 
Daleandee said:
Take a look at oil analysis also. As @Jim K noted above, a few minute flakes are not unusual but if you find pieces with part numbers then there is a concern ...
Click to expand...
Would you be mad if your mechanic put this in your engine logbook? Be like doing an annual then putting all the discrepancies that weren’t fixed and didn’t have to be fixed for an airworthy plane in the planes logbooks.
 
bonefishpete said:
Would you be mad if your mechanic put this in your engine logbook? Be like doing an annual then putting all the discrepancies that weren’t fixed and didn’t have to be fixed for an airworthy plane in the planes logbooks.
Click to expand...

Well I do have an advantage as I tell the mechanic exactly what I want written in the engine logbook and he does it ... :smilewinkgrin:

It's experimental and I'm the mechanic
 
SixPapaCharlie said:
Every oil filter I have cut open for 10 years has had some glitter in it.
Click to expand...
That. But so many log entries state "no metal found", skewing our perception.
I asked my IA how will I know when the engine is "making metal". His reply was "you'll know it when you see it". A few months later he showed me the filter from an engine that was making metal - I understood what he meant. It was like looking at metallic paint mixed with oil.
 
You must log in or register to reply here.
Back
Top