Return of Investment in Oil Analysis

[Jaybird180]

Does it provide any real world value? A poster here had recent engine work done, but the analysis didn't indicate an issue. It was metal in the filter, which would have been seen regardless.

I am interested in real word results that indicates the oil analysis provides better decision making about TBOH intervals versus cool data to gawk over.

 

[OkieAviator]

Not sure what you're asking... it can so quite a number of things, excess iron, metals, ect... If you want to save the 50 cents a flight hour then don't utilize it.

 

[Checkout_my_Six]

all depends on the physics of failure....and the size of the metal that failure mode produces.

Oil analysis will not and does not indicate for all failure modes....

 

[Brad Z]

Does it provide any real world value? A poster here had recent engine work done, but the analysis didn't indicate an issue. It was metal in the filter, which would have been seen regardless.

I am interested in real word results that indicates the oil analysis provides better decision making about TBOH intervals versus cool data to gawk over.

It's one piece of the puzzle. Like a doctor ordering blood tests, oil analysis MAY provide provide an indication of what's going on inside. The difference for aircraft owners is doing regular oil analysis and examining changes in metal content to spot trends in wear.

It's not perfect, but it's one tool to give the owner a sense of confidence in the condition of the engine.

 

[yetti]

http://www.avweb.com/news/profiles/182855-1.html

 

[Tom-D]

Just a quick question..

You have a long term history of normal analysis, then a spike of high metal, which continues 3-4 oil samples.

Who is willing to tear down the engine to see why?

 

[gov98]

... I don't know I tend to think there's a substantial potential return for ongoing oil analysis...not necessarily in tear-down choices etc., but more simply if you are able to show a buyer that you have 8 consecutive 50 hour intervals of normal oil analysis, it will provide some degree of confidence that the engine is, at least at the time of purchase, healthy.

To me, the biggest fear that the buyer has of an airplane, is...this guy is selling because his mechanic said he has some major problem that I'm going to get saddled with, if the seller can reduce that concern to the buyer...then they can probably more effectively sell the plane, and it may not get more $, but it may cause the days on market to be less.

 

[Rcmutz]

Oil analysis will show wear of internal components. All metals will wear during usage. What you don't want to see is a spike in wear metals. If you do, to me, it is an indication to begin to keep and eye on things. Combined with compression testing, filter inspection, and boroscoping, you have a lot at your disposal to keep an eye on your engine, and make some sort of intelligent decisions on cylinder/component replacement versus tear down. I don't think you will tear down an engine just because of what oil analysis says. It is one part of a total maintenance "inspection" plan. For full disclosure, I don't do oil analysis every oil change. Once a year at annual, comparing year over year trends, which is about 40-50 hrs. If something comes back high, I may go to more frequent oil analysis. Just my 3 cents.

 

[Jaybird180]

http://www.avweb.com/news/profiles/182855-1.html

Thank you for that

 

[Checkout_my_Six]

Just a quick question..

You have a long term history of normal analysis, then a spike of high metal, which continues 3-4 oil samples.

Who is willing to tear down the engine to see why?

Tom I can't imagine anyone just tearing into an engine with just oil analysis info.

I certainly would begin an investigation to determine the source of the elevated wear metals....also I'd inspect the filter and sump screens.

If I had elevated metals with low oil pressure and saw nothing with a visual borescope I might be inclined to do surgery....but it'd be a last resort.

 

[Chip Sylverne]

Tom I can't imagine anyone just tearing into an engine with just oil analysis info.

I certainly would begin an investigation to determine the source of the elevated wear metals....also I'd inspect the filter and sump screens.

If I had elevated metals with low oil pressure and saw nothing with a visual borescope I might be inclined to do surgery....but it'd be a last resort.

At every oil change filter and screen are inspected anyway. And cylinders are (or should be) borescoped at annual. And low oil pressure is a red flag all on it's own. Oil consumption increased, there's compression tests and case pressure to look at.

So what does oil analysis provide but increased stress over numbers that may or may not mean anything?

 

[Brad Z]

Just a quick question..

You have a long term history of normal analysis, then a spike of high metal, which continues 3-4 oil samples.

Who is willing to tear down the engine to see why?

It depends. What is the metal that's spiking? How are compressions, oil consumption, bore scoping, filter paper, etc?

Depending on the amount of time on the engine, if I couldn't rule out anything else obvious, I might consider throwing in the towel on the engine. After all, I fly this thing with my family in IFR, at night, etc. if I have any reason to question my confidence in the engine, I'm going to investigate further. I never have 100% confidence in any engine, but hey, if an engine is trying to tell me something, I'm going to listen.

 

[Tom-D]

It depends. What is the metal that's spiking? How are compressions, oil consumption, bore scoping, filter paper, etc?

Depending on the amount of time on the engine, if I couldn't rule out anything else obvious, I might consider throwing in the towel on the engine. After all, I fly this thing with my family in IFR, at night, etc. if I have any reason to question my confidence in the engine, I'm going to investigate further. I never have 100% confidence in any engine, but hey, if an engine is trying to tell me something, I'm going to listen.

If you wouldn't use it as a sole reason, why buy it?

 

[Checkout_my_Six]

If you wouldn't use it as a sole reason, why buy it?

It's an indicator.....one of many flags that cause one to begin the investigation.

I don't know of many indicators that provide a "sole" reason to tear into an engine.

 

[Chip Sylverne]

It's an indicator.....one of many flags that cause one to begin the investigation.

I don't know of many indicators that provide a "sole" reason to tear into an engine.

But the investigation consists of things you are, or should be, doing anyway.

 

[Brad Z]

If you wouldn't use it as a sole reason, why buy it?

Buy what?

 

[Checkout_my_Six]

But the investigation consists of things you are, or should be, doing anyway.

yup....the oil analysis provides more information.

I'd hope a doctor didn't do surgery on the results of blood work alone....

 

[Tom-D]

It's an indicator.....one of many flags that cause one to begin the investigation.

I don't know of many indicators that provide a "sole" reason to tear into an engine.

Metal in the oil? that's enough for me.

 

[Tom-D]

Buy what?

you don't think you buy each of the oil sample kits?

Or are you thinking you can grab a hand full of oil and run it over to the lab and they'll do it for free?

 

[Checkout_my_Six]

Metal in the oil? that's enough for me.

no wonder you overhaul all those engines....

so Tom....what do ya suppose happened after this engine began making metal? (see the red circle)

Was it overhauled?....repaired?....or some other maintenance?

 

[Let'sgoflying!]

>24hrs and not one post "I/a friend had a high metal report in the oil analysis and the engine cratered/needed internal repair soon after".

Neither have I heard of such reports in the past (Mr Fenton's excepted) and have lost faith in the test as being something 'obviously useful'.

 

[Tom-D]

so Tom....what do ya suppose happened after this engine began making metal? (see the red circle)

Was it overhauled?....repaired?....or some other maintenance?

Is this a trick question? Read the "comments" section of the report.

 

[Tom-D]

no wonder you overhaul all those engines..

"All those engines" .... yeah right.


When we have time I'l document why I recommend tearing the engine down at first sign of metal in the oil.

Or

You can prove it to your self. Find me a 0-300-A crank in serviceable condition.
Or
Find me a 0-320-E2D crank in serviceable condition.

and quote prices and delivery times.

 

[Silvaire]

The original question is a cost analysis. Is it worth it? Are you gonna come out ahead in the end?

In general aviation these questions amount to nothing less than nonsense. You're not doing this to make or save money, you're doing it to get rid of the pestilence that is wealth

 

[tsts4]

The original question is a cost analysis. Is it worth it? Are you gonna come out ahead in the end?

In general aviation these questions amount to nothing less than nonsense. You're not doing this to make or save money, you're doing it to get rid of the pestilence that is wealth

Exactly. I see oil analysis as just another tool in the toolbox. At $28 per report, a cheap one at that. Trying to couch it in terms of ROI seems useless to me.

 

[denverpilot]

Exactly. I see oil analysis as just another tool in the toolbox. At $28 per report, a cheap one at that. Trying to couch it in terms of ROI seems useless to me.

Why not? I see what the OP is asking.

If you multiply the $28 by the number of oil changes in the lifespan of a typical engine, how large would that number be that could have been spent on the eventual repairs or other things for the aircraft?

(I'm not arguing it's worth it or not worth it. I'm rephrasing the question so you know what he's asking.)

 

[tsts4]

Why not? I see what the OP is asking.

If you multiply the $28 by the number of oil changes in the lifespan of a typical engine, how large would that number be that could have been spent on the eventual repairs or other things for the aircraft?

(I'm not arguing it's worth it or not worth it. I'm rephrasing the question so you know what he's asking.)

Come on. My oil changes cost me roughly $80 a pop. Another $28 on top of that is chump change when you consider the annual costs of databases, gas, insurance, hangar rent, etc. Bottom line is flying is expensive. It really boils down not to the actual cost over time but the value. If the analysis is valuable to you the investment will be worth it. Does hull insurance provide a worthwhile ROI?

 

[Stewartb]

I have no interest in oil analysis. It may work if you fly a consistent number of hours in a consistent time period and change oil at consistent intervals. Outside of that the variables would be too great to use the information. I don't know anyone who does analysis.

 

[Checkout_my_Six]

Is this a trick question? Read the "comments" section of the report.

It's my report. No trick question and that engine was never torn down or rebuilt.....and nay on a cylinder being removed.

So....would you have torn into that knowing that information?

Obviously whatever was done worked......

 

[Jaybird180]

It's my report. No trick question and that engine was never torn down or rebuilt.....and neigh on a cylinder being removed.

So....would you have torn into that knowing that information?

Obviously whatever was done worked......

I'd start looking for the source of the silicon. And knowing we have an abundant source on this planet, I'd tear into the air filter, run the engine another interval and measure again.

I might also run a compression test and consider a borescope as I'm suspecting sand contamination.

 

[Tom-D]

It's my report. No trick question and that engine was never torn down or rebuilt.....and neigh on a cylinder being removed.

So....would you have torn into that knowing that information?

Obviously whatever was done worked......

Did you see metal in your oil?
Do you now know why we need a trend to make case for teardown?

If you don't believe it is a useful tool why buy it?
If you do believe the results, Why wouldn't you tear it down?

 

[Tom-D]

This was a metal generating failure, Ya think the next oil sample would show any thing?

 

[Tom-D]

This is the crank removed from that engine 10 hours later.

 

[Chip Sylverne]

I'd start looking for the source of the silicon. And knowing we have an abundant source on this planet, I'd tear into the air filter, run the engine another interval and measure again.

I might also run a compression test and consider a borescope as I'm suspecting sand contamination.

Don't you check your filter and change it according to the MM interval, and check the induction system (and carb heat flapper) for leaks at least every annual, along with a borescope and compression test?

I will admit that a good looking trend in oil analysis makes for a pretty tool when selling your bird, and for that maybe it's worth the $, but I'm not selling anytime soon.

 

[Checkout_my_Six]

Don't you check your filter and change it according to the MM interval, and check the induction system (and carb heat flapper) for leaks at least every annual, along with a borescope and compression test?

I will admit that a good looking trend in oil analysis makes for a pretty tool when selling your bird, and for that maybe it's worth the $, but I'm not selling anytime soon.

It sure did help sell my Six

 

[Checkout_my_Six]

Did you see metal in your oil?
Do you now know why we need a trend to make case for teardown?

If you don't believe it is a useful tool why buy it?
If you do believe the results, Why wouldn't you tear it down?

No metal in the filter or sump ......just the oil analysis.

So Tom are you tearing into an engine just using oil analysis? I'm not.

 

[Tom-D]

No metal in the filter or sump ......just the oil analysis.

So Tom are you tearing into an engine just using oil analysis? I'm not.

I'm tearing into the engine when I see metal. Way too many times the sample will not show the impending failure.

but when it does

 

[denverpilot]

Come on. My oil changes cost me roughly $80 a pop. Another $28 on top of that is chump change when you consider the annual costs of databases, gas, insurance, hangar rent, etc. Bottom line is flying is expensive. It really boils down not to the actual cost over time but the value. If the analysis is valuable to you the investment will be worth it. Does hull insurance provide a worthwhile ROI?

Again I'm not arguing either side, but you're not answering the question the OP asked. The ratio of oil cost to testing costs was not part of the question.

The question was how much money is spent over the lifespan of an engine on testing that shows nothing, and is it the testing showing a problem or another subsequent event that would happen anyway, that usually triggers the teardown.

The question is exactly what you want. A value question.

That we all spend a lot of money on things is also not relevant to the question asked.

 

[tsts4]

Again I'm not arguing either side, but you're not answering the question the OP asked. The ratio of oil cost to testing costs was not part of the question.

The question was how much money is spent over the lifespan of an engine on testing that shows nothing, and is it the testing showing a problem or another subsequent event that would happen anyway, that usually triggers the teardown.

The question is exactly what you want. A value question.

That we all spend a lot of money on things is also not relevant to the question asked.

OK but you were the one who brought up cumulative cost. I simply provided an example to show that the cost was IMO, negligible over time in context to the overall cost of ownership. I also stated that value was what was important. Again IMO oil analysis is kind of like insurance in that if you never have to use you'll never see any kind of tangible return

 

[JimNtexas]

To me this sounds like 'what is the ROI on your shoulder harnesses'?

It's certainly true that oil analysis WILL detect some impending failure modes before the failure happens, but it's not omniscient, omnipresent, and omnipotent.

Just like it's certainly true that a shoulder will reduce the chance of you eating your instrument panel in some failure modes of the engine. But not all.

Each owner should weigh the evidence against his experience and type of flying, and decide how much he or she wants to spend on non-required safety precautions.

I reject the premise of the question.