The International Cessna^® 170 Association

Do many use oil analysis? Who do you use? I want to keep check on my oil as I breakin this new cylinder and keep check on the others.

John

I don't believe oil analysis is recommended during break-in

I would strongly encourage oil analysis. One sample is not enough. I do it every oil change. The beauty behind Oil analysis is that you will identify trends in engine wear. You will easily identify problems long before the engine goes south. The important part about analysis is consistancy. It has been an important part of engine health and maintenance on everything I have ever worked on or flown. YMMV. Doug

Be carefull with oil analysis. Last year I had one come back with extreme high metals showing in the red. Only had about 250 hrs since complete rebuild. It was enough my mechanic took the report to the engine builder who decided it was best to tear it apart and split the case. Long story short, nothing wrong. Inspected every part down to the last nut bolt everything. Engine runs like a champ just like it did before and the last few samples have been normal with the previous samples. I tried to contact the sample company but still have never heard back from them. I now worry that someone else got a good sample back while I got their bad one...
It cost a bit of cash to tear down a engine on a bad report.
Greg

canav8 wrote:...You will easily identify problems long before the engine goes south. ...

Not always. Catastrophic failures can occur between samples and that means no warning from spectro-analysis at all.

You are correct about regualar sampling, however. Unless the samples are taken regularly, consistently, and analyzed by the same laboratory using the same consistent techniques.... they are a waste of money.

History:
Oil analysis became popular in the early days (1960s/70s) of turbine engine development when everyone was afraid of those expensive jets which were coming into the market. After a while, jet/turbine engine manufacturing and operating became mature and development problems went away and the analysis labs services were no longer required and folks quit using them. (Except for the Honeywell people who require it of their warranty-holders, at the owners expense. They call it MSP (for Maintenance Service Plan) but operators/owners call it Money Sent-to Phoenix, since Honeywell has their engine shop there. Typically it can discover a bearing that is wearing.

The laboratories weren't making the profits they had been making when people were scared of turbines.

Opinion:
Then someone decided the service could be sold to recip owners too!

While marketing types from spectro labs have horror stories of everyone who doesn't use their services, and happy ending stories about those that do...(the happy endings are odd...they tell of folks happy to discover their engines have excessive or abnormal wear....and attempts are made to tell them exactly which part is wearing. Odd thing about this is that it still requires an engine tear-down to fix the problem, which would just as likely be found by ordinary operations and oil screen/filter exams.)

The hope is that the laboratory can be a sooth-sayer to tell you to quit flying at night and over-water...in fact, quit flying all together and tear your engine down prematurely...before you see metal in the oil.

Those who find out their engines are dying from oil analysis swear by the process.
Those who find out by other means.... have the same outcome....they buy engine repairs.

Many more folks change oil regularly and never have a problem at all.
Otherwise, the process provides a sense of security to those who subscribe to the service.
Until their engine goes "clunk" in the night.

Personal Recommendation:
Save your money for 25-hr oil changes, spin on filter adaptors, and a filter-opening tool. Look at the filter media every 25 hours, religiously. Be your own laboratory. Don't worry about things in your oil so tiny you can't see it.

Save your money for 25-hr oil changes, spin on filter adaptors, and a filter-opening tool. Look at the filter media every 25 hours, religiously. Be your own laboratory. Don't worry about things in your oil so tiny you can't see it.

And that pretty much sums up what I have gone to. After a tear down and couple more samples to conclude that nothing was wrong to start with, I now am getting a good idea what gets caught in the filter is a good place to start. I run a magnet up and down every filter fold now after I have the filter cut. My filters are pretty clean I think, once in a while a tiny tiny piece of dirt or something, but no part numbers on chunks

Omigod! Don't tell me that people are starting to catch on to this "Oil Analysis" business!

blueldr wrote:Omigod! Don't tell me that people are starting to catch on to this "Oil Analysis" business!

Yep. Lately, even the fast-oil-change place in the next town to me is high-pressure-selling it to housewives and their dummies for the Lexus and their SUVs.

(These are the same folks who also sell "pure nitrogen" for their tires, telling them it will save their tires, save gas mileage, and help prevent hydroplaning and assist braking by keeping the tire pressures better maintained... "and it's what they use in ALL AIRPLANES!" (Yep. I guess I should be outed that I've been advising all you guys while secretly putting ordinary compressed air in my tires.)

I explained to one of the housewives that ...if the atmosphere is already 78% nitrogen...and if some of the smaller molecules of other gases leak out of tires more rapidly than that nitrogen.... then the concentration of nitrogen remaining in the tire is MORE than 78%. Right?

THEN...if we put more ..."ordinary compressed air" (which is 78% nitrogen) into her tires.... then : "Isn't the concentration of nitrogen inside that tire higher than originally?...and doesn't it concentrate more and more with each addition of ordinary compressed air....???

Man! You should have seen the nasty looks the service salesman gave me when he failed to get her to pay $99 to service her tires with "pure nitrogen".