Oil too clean?

[NicoN]

Over the last year we did a little maintenance, by overhauling both Mags and cleaning the vernatherm valve.

We always see higher oil temperature than we want. In summer oiltemp can go up to 215-220.

The above measures did not change this behaviour.

But, now for the third time, the oil looks after 50h more or less unused, a bit grey but definitively not black as it was before.

Also we see almost no oil consupmption. If you fill it up above 6, it will be at 6 at the next oil chekc and stay there for a long time.

 

One of my partners is concerned; he says, we have not sufficient lubrication as the oil looks "too good"

 

What is the opinion of the experts? We have the TSIO360-GB engine

[KB4]

Send in an oil sample for analysis and pull the oil screen to see if anything is clogging that. Zero oil burn on an air cooled engine sounds strange to me but I’m no expert.  

[A64Pilot]

Someone sneaking in and changing oil?

In theory an air cooled aircraft engine does need to burn some oil, but I have never heard of it causing a problem if one consumes little oil.

My SWAG is you have a very newish tight motor, so enjoy it

I called Exxon years ago about my high oil temp concerns wanting to know if I should shorten change intervals. I was told that the temp limits were engine limits  and the oils limits were way higher, so worry about the temps maybe, but not the oil. So I called Lycoming and was told my temps were fine as long as I wasn’t redlining there wasn’t a problem.

What oil are you using? be sure it’s not Non Detergent oil, “break in” oil doesn’t suspend the particles and may not turn black as fast. 

 

Edited August 31, 2021 by A64Pilot

[NicoN]

"no oil consumption" is a bit too ambitious. We still have a little oil sweating on the valve covers. So, we are losing a bit of oil over time; but almost nothing. Has been way more.

Where does this oilscreen sit?

[ArtVandelay]

Not sure if it matters, but what kind of oil are you using?


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[A64Pilot]

5 minutes ago, ArtVandelay said:

Not sure if it matters, but what kind of oil are you using?


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I think it can matter, many people think when their oil turns color fast their oil isn’t as good as it should be, they think a good oil will stay clean looking longer.

Just the opposite is true. A good oil will disperse the carbon etc and turn color more quickly.

But anyway that’s why I asked if by chance he was still using break in / non AD oil.

I guess I should have also asked how many hours on the motor.

Edited August 31, 2021 by A64Pilot

[tmo]

FWIW my TSIO-360-LB1 doesn't seem to use much oil at all; I add maybe a quart between changes, but really just to feel better. Phillips 20W50 + Camguard.

[EricJ]

+1 on sending it in to start oil analysis trending.    Not turning black just means you're not getting a lot of blow-by now, which is good.    If it's pumping and you have good oil pressure and your temps are normal, you're getting good lubrication.    Consumption has essentially nothing to do with lubrication.

 

[carusoam]

After we had our engine remanned…

The only oil in the case was brand new…

Most of our flying was LOP and long distances…

The oil always was soooo clear, it was a challenge to read the level reported on the dip stick.

 

hmmmm…. Did anyone rinse the old oil out of the case… a practice known to be done by some pilotos…

 

PP thoughts only, not a mechanic…

Best regards,

-a-

[Anzaldi01]

For what it's worth I did an overhaul early this year. The engine shop sent Phillips 66 XC 20W50 back with the engine so that's what I started using. In the past it was AeroShell 100W+. I'm please with the Phillips product and will continue to use it. 

 My engine has about 130 Hours on it now and the oil changes also reflect much cleaner oil drains. Filter has been clean and the Oil Temps are within the normal range. Eric J. Comment about less blow by with the fresh engine is absolutely accurate. I wouldn't worry about the oil being too clean, overall it will prolong the life of the engine and it sounds like you did a good break in with the low oil consumption. 

Sincerely,

Carl

   

[PT20J]

Where does oil go? If it's not leaking, or blowing out onto the belly, it has to be getting burned in the combustion chamber. If the valve guides don't leak, most of the oil that gets burned comes from the cylinder walls. Lubrication is required to prevent cylinder and ring wear. The rings are supposed to skate on a very thin film of oil. Some of that oil gets burned up with each combustion event. Too much oil getting to the combustion chamber causes high oil consumption, fouled plugs and carbon build up. Too little causes excessive ring and cylinder wear. Each engine is unique (within a range). Yours might be fine. Oil analysis over time will tell if the wear is abnormal. I would be concerned if it changed a lot (up or down) and I hadn't done anything to explain it because that would indicate that something in the engine is different.

Things that increase oil consumption are high temperatures (because of lowered viscosity) and higher rpm (greater frequency of combustion events).

I've heard from several sources that Continentals usually use less oil than Lycomings. Apparently oil can make a big difference: personally, in my Lycoming factory rebuilt  IO-360-A3B6, I went from 8-9 hours per quart using Aeroshell W100 to 12-14 hours per quart using Phillips 20W50.

Skip

[KB4]

8 hours ago, NicoN said:

Where does this oilscreen sit?

In the 360, its 6” or so from the firewall on co-pilot side near bottom. Check that your engine has 1, if so will be near the oil pan is my guess.   Was a really great video around here on removal and safety wiring the screen but I couldn’t find it. 

[Skates97]

5 minutes ago, KB4 said:

In the 360, its 6” or so from the firewall on co-pilot side near bottom. Check that your engine has 1, if so will be near the oil pan is my guess.   Was a really great video around here on removal and safety wiring the screen but I couldn’t find it. 

Here you go.

 

[EricJ]

8 hours ago, NicoN said:

Where does this oilscreen sit?

If you have a spin-on oil filter, then you don't have a pressure screen.    You can cut the filter open during an oil change, cut the media out, and inspect it for metal particles.  Running a magnet over it make it fairly easy.   There are videos online of different ways to remove the filter media and check it for metal.

I think all K models have a spin-on filter, but for engines without them there will be a pressure screen instead that can be removed and checked.    

[dan nephin]

5 hours ago, tmo said:

FWIW my TSIO-360-LB1 doesn't seem to use much oil at all; I add maybe a quart between changes, but really just to feel better. Phillips 20W50 + Camguard.

+1

[DanM20C]

17 minutes ago, EricJ said:

If you have a spin-on oil filter, then you don't have a pressure screen. 

The Continental IO360's have a suction screen.  It's not really a screen but a perforated tube, It only protects the oil pump from the really big stuff.

My TSIO-360-LB1 also doesn't use much oil.  I'm at 25hrs since last oil change and have only added 1/2 qt about 5 hrs ago.  Also stays very clean.  125 SMOH.

Cheers,

Dan 

[Guest]

9 hours ago, NicoN said:

"no oil consumption" is a bit too ambitious. We still have a little oil sweating on the valve covers. So, we are losing a bit of oil over time; but almost nothing. Has been way more.

Where does this oilscreen sit?

There is an oil suction screen on the back left corner of the accessory housing, and the pressure oil filter on the centre of the accessory housing.

During oil change pre fill the filter with oil before installing it.

Clarence

[INA201]

After getting almost all parameters of engine maintenance and engine management dialed in the oil in my 1978J stays very clear and starts to slightly brown by 30hours. I’ve done everything from perfecting the timing, rebuilding mags, oil cooler overhaul, plug wires, engine monitor, induction clean up, new baffling, etc. She runs too good, Knock on wood!  Before all of this the plane would burn more oil and the oil would turn dark prematurely imop.   

[Guest]

39 minutes ago, KB4 said:

In the 360, its 6” or so from the firewall on co-pilot side near bottom. Check that your engine has 1, if so will be near the oil pan is my guess.   Was a really great video around here on removal and safety wiring the screen but I couldn’t find it. 

It might be on your Lycoming, but the OP owns a K with a Continental engine.

Clarence

[KB4]

5 minutes ago, PT20J said:

I went from 8-9 hours per quart using Aeroshell W100 to 12-14 hours per quart using Phillips 

21 minutes ago, M20Doc said:

There is an oil suction screen on the back left corner of the accessory housing, and the pressure oil filter on the centre of the accessory housing.

During oil change pre fill the filter with oil before installing it.

Clarence

Always on point. 

[PT20J]

Another filter inspection trick that my IA showed me is to remove the pleated media and wrap it in a couple of paper towels and compress it in a bench vice which squeezes out the oil and makes it really easy to see any metal fragments. 

Skip

[jetdriven]

I let the filter sit upside-down for a couple days and drain out, then I cut it remove the filter media and if you really want to see what's going on wash it in a half a quart of mineral spirits and then put a magnet under the cup and pour off the liquid

[EricJ]

1 hour ago, DanM20C said:

The Continental IO360's have a suction screen.  It's not really a screen but a perforated tube, It only protects the oil pump from the really big stuff.

My TSIO-360-LB1 also doesn't use much oil.  I'm at 25hrs since last oil change and have only added 1/2 qt about 5 hrs ago.  Also stays very clean.  125 SMOH.

Cheers,

Dan 

Yes, the suction screens aren't much good for assessing metal production unless it's really bad, i.e., making big chunks.  The joke is that those catch parts with serial numbers.   If the oil filter (or pressure screen on some engines) doesn't have much metal, I think there's very limited value in checking the suction screen every oil change or very often.    I've had mine off once in three years.      ymmv

[Guest]

9 minutes ago, EricJ said:

Yes, the suction screens aren't much good for assessing metal production unless it's really bad, i.e., making big chunks.  The joke is that those catch parts with serial numbers.   If the oil filter (or pressure screen on some engines) doesn't have much metal, I think there's very limited value in checking the suction screen every oil change or very often.    I've had mine off once in three years.      ymmv

They do require inspection.  I had a Lance in my shop that was having weird oil pressure fluctuations, it turned out that the suction screen was almost full of carbon particles from years of never being cleaned.

Clarence 

[PT20J]

What do maintainers have that most of don’t: knowledge, experience and practice? There are threads here lamenting the difficulty of removing and reinstalling the suction screen on a M20J. My IA did it in the blink of an eye. I am always amazed at how quickly a competent, experienced person can do things that look nearly impossible to me.

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