Metal in the filter, diagnostics and corrective action

Tom-D said:
That is a nice article, have you any training as to interpret your findings? all valves do not look as nice as pictured there.

OBTW you didn't answer my question.
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people always complement me on my valve analysis.....:yes:

Tom....I've been doing failure analysis for +25 years. It's what I do. :D
 
Tom-D said:
Show me a definitive description of what you are supposed to see.

OK let's say you see some discoloration of a valve, are you going to allow me to pull the Cylinder and send it out for repair?
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That was what I was getting at earlier too. The folks I know of that have had warning signs show up in an oil analysis didn't want to do anything about it because there were no other signs of a failure. What good does an oil analysis or valve inspection do if you're just going to ignore it and keep running the engine anyway? :dunno:
 
nrpetersen said:
I've seen that too. Made minor metal for a long time on a C-150. What happens if it is ignored?
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I've seen it as well. We had an O-540 that was making aluminum for a long time. We followed the Lycoming service bulletin to the letter and when it got to the point of suggesting a disassembly we did. Nearly every piston pin plug showed evidence that it was shedding metal. The engine got topped and it has been fine since (there were other reasons that cylinder replacement was suggested as well).

One theory as to why the piston pin plug wear happens that I've heard is that the piston pin travels below the swept area of the piston rings. If there is any ridge at that point it may knock off some metal as it passes by. I've never seen a cylinder worn bad enough to have an obvious ridge but the theory seems like a reasonable one to me.
 
Checkout_my_Six said:
people always complement me on my valve analysis.....:yes:

Tom....I've been doing failure analysis for +25 years. It's what I do. :D
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Do you believe every one is as good as you are? your advice is for every one is it not?
 
mondtster said:
That was what I was getting at earlier too. The folks I know of that have had warning signs show up in an oil analysis didn't want to do anything about it because there were no other signs of a failure. What good does an oil analysis or valve inspection do if you're just going to ignore it and keep running the engine anyway? :dunno:
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You just described 90% of the GA owners.
 
Tom-D said:
You just described 90% of the GA owners.
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You bring up good points. I think symptoms of a stuck valve should get immediate action (IA). A mushroomed valve, (IA), a scored cylinder, (IA). Discolored valves, tougher call. Chips in filter, definite concern, should be investigated.

Do you have any guidelines?
 
PaulS said:
You bring up good points. I think symptoms of a stuck valve should get immediate action (IA). A mushroomed valve, (IA), a scored cylinder, (IA). Discolored valves, tougher call. Chips in filter, definite concern, should be investigated.

Do you have any guidelines?
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when I see metal in the oil, I automatically think "SAVE THE CRANK" those critters are expensive. Continued operation in these cases is in my humble opinion a penny smart and pound foolish.

If in this case were it my engine it would be off and apart by now.
Guidelines ?? follow the manufacturers MM and SBs it is all there, what and how to do.
 
Tom-D said:
when I see metal in the oil, I automatically think "SAVE THE CRANK" those critters are expensive. Continued operation in these cases is in my humble opinion a penny smart and pound foolish.

If in this case were it my engine it would be off and apart by now.
Guidelines ?? follow the manufacturers MM and SBs it is all there, what and how to do.
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Thanks.
 
AdamZ said:
So I get the filter look see and the oil analysis on each change. Are you suggesting a boroscope and compression at each change as well or just upon annual or finding something?
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Just at annual or finding something. Although if you find metal, you have to find out where it is coming from. Boroscoping is not difficult and may lead to a finding. In my case we did not see anything wrong with the valves, seats, or cylinder walls, so we ended up pulling one cylinder at a time till we found it, unfortunately on the 4th one. Of course if we didn't the next step would of been splitting the case, and a major overhaul. :yikes:

The good news, we were able to inspect the cam lobes and everything looked great. :)
 
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