[Flybipe]

I recently purchased a plane with an AEIO-360-A1E with 682 TTSN. The oil was last changed in 2005. It had been annualed, and ferried to my location, where I pulled an oil sample and changed the oil.

My analysis came back with high concentrations of Iron (220 ppm) and aluminum (43 ppm) and moderate concentrations of chromium (19 ppm).

The lab suggested abnormal cylinder wear and recommended pulling a sample in 25 hours for re-analysis. The technician suspected that the iron could have been rust, and the rust could have caused the premature cylinder wear.

Does anyone have any recommendations for what I should look at first in trying to determine where these higher than normal concentrations are, and is this something that should be expected to return to normal after a fresh oil change and frequent use?

Good Flying,

Josh P.

 

[tommylewis]

oil analysis

Alot of airplane owners swear by Marvel Mystery oil for "older" engines. Consider putting a quart in, running for 20 hours, then retesting.

 

[mannanj]

Oil

Fly:

How long did the engine sit idle between running????? Rust can also build up on the Camshaft and Cam Followers (Lifters).

I got a very good buy on a Lycoming for my RV from a 201 Mooney. It had 2 spalled Cam Lobes and 4 Lifters. I was helping a buddy who is an A & P Mechanic with Inspection Authorthization do an Annual Inspection on the plane.

It had low compression and had to send two Cylinders off to be repaired--the plane and engine only had just over 1300 hours total time since new. The Engine Shop called and said "check the Cam". The Piston Skirts had chunks of imbedded steel in them.

I bought the engine from the owner, who wanted a new engine. I had to replace the Camshaft and Followers, send the oil cooler off to be flushed, along with the rest of usual Overhaul Protocall done to "Yellow Tag" an engine to "0 time since Major Overhaul".

This is a long story to suggest that one of the things you might want to check into is the Cam-Lifter section of your engine.

 

[John Clark]

Disuse

I recently purchased a plane with an AEIO-360-A1E with 682 TTSN. The oil was last changed in 2005.

What you have is an engine suffering from disuse. You didn't mention the year of the engine, but at 682 TTSN and 3 or 4 years since an oil change I suspect that the engine is rusty. My advice would be to pull one cylinder and look at the camshaft. You may not be happy with what you see.

John Clark
RV8 N18U "Sunshine"
KSBA

 

[asav8tor]

1. Where was the engine located during the last 3 years? Big difference between Hanger in AZ and a Tie down on the coast.

2. I would cut the filter rinse in gas and run a magnet around in the gas.

3. Pull the suction screen and inspect.

Then if nothing significant....

I would fly 20 hours,

Oil & Filter change
Oil sample
Oil filter cut
Oil suction screen


Then fly 20 hours, repeat

With 3 iterations, 60 hours, if I didn't see the items of concern trending down and or found significant fuze sticking to the magnet I would O/H.

No significant fuze and metal trending down, go to 25 hours and keep on flying.


One oil sample is a snapshot. Several snapshots make a movie. Easy to tell you what to do with a movie. Not easy with only one snapshot.

 

[Flybipe]

Thanks for the info. The engine is a 1991. The oil was changed in PA, then the plane was flown to Temecula CA (near the coast), where it sat for the last 2 years. The engine doesn't have a filter, but the screens are completely clean.
Josh P.

 

[RScott]

I did oil analysis for the Air Guard for 18 years--on jets, of course, not piston engines. I have access to a spectrometer & run samples for my friends.

Most of the samples from friends' Lycomings have come in at under 20 ppm for engines flown regularly, under 100 ppm for engines that sit a lot in the winter for iron, under 15 for aluminum, regardless of how often flown and under 15 for chromium.

One sample tells you very little. As others have suggested, there was probably some rust. Given the above numbers, I suspect there wasn't a lot of rust.

And as others have suggested, I would fly it and pull another sample after 20 or so hours.

Rust should have been scraped off parts subject to friction when it was flown. If the engine is basically healthy, fresh oil and flying again should give normal numbers. If you do get higher than usual readings, it's time to look inside the engine.

"Experts" advise taking your sample about midstream as it drains. Just for a test, however, we sampled from a filter and compared that with the oil we caught as it drained. No difference. The filter captures particles that are of a different size from what the spectrometer reads. So if any of you forget to catch a sample as it drains, you can take oil from the filter and get usable results. It's not what they recommend, but it works.

Use the same lab you used before. Different labs use different spectrometers and get different readings.

One sample doesn't tell you very much; it's the trend over time, sample to sample that tells the story. If you want to switch labs, wait until you have this sorted out.