Interesting oil change observation

[rbridges]

Not really mooney related, but kinda.  I built a house last year with a generac generator. I did the annual oil change yesterday. The generator does a monthly test run for 5 minutes or so. The oil was gold but somewhat opaque/milky. I knew it wasn't coolant but wondered why moisture would be in it. I googled and several people mentioned the same thing. They said it was from lack of runtime and not heating the oil enough to boil put moisture.  That's the first time I've ever seen that. Just an interesting observation. I see how that could be a problem for planes that sit around. 

[takair]

Did it look like this?  Not from my plane....but I suggested to this pilot that they fly more or save for a new cam. (More frequent oil changes and more heat I. The oil may help too)...  No, the leaf and other junk didn’t come from said filter...lol.

[carusoam]

That is why ground runs are not the same as taking the plane around the pattern...

The large amount of moisture that is the by-product of combustion... doesn’t get completely driven out...

 

Is there a way to take the Generac around the pattern better?

 

there may also be some rough surfaces on the cylinder walls entraining some exhaust in the oil....?

 

Pure PP guesses... no real knowledge of the situation...

Best regards,

-a-

 

[rbridges]

1 hour ago, takair said:

Did it look like this?  Not from my plane....but I suggested to this pilot that they fly more or save for a new cam. (More frequent oil changes and more heat I. The oil may help too)...  No, the leaf and other junk didn’t come from said filter...lol.

wow, that's awful.  Mine wasn't that bad.  Just could tell it wasn't clear through and through.  When I drained it and looked at it in a plastic cup, it looked like it was a suspension.  

[eman1200]

@AGL found some metal in the oil filter. Does this look ok until next oil change?

[Bunti]

I think, I would further investigate the source of all the flakes  before flying again.

[David Lloyd]

That's ugly Eric.  Hope Lynn swept that from under his drill press.

[Hank]

2 minutes ago, Bunti said:

I think, I would further investigate the source of all the flakes  before flying again.

Looks like it's from a milling machine . . . . Whatcha makin?

[carusoam]

When recycling the cutting oil from the milling machine...

It is tradition to filter it first before re-using it in any airplane...

 

Oddly... nothing big enough to have a legible part number on it.

 

Hmmmm....

Loose wrist pins have made a similar mess.... (big stretch of an old memory....)

Good luck finding the source... hopefully it is localized to one spot....   but, that is a lot of metal that may be everywhere.... and need serious cleaning...

Now rechecking today’s date to make sure it isn’t April first.... 

PP thoughts only... not a mechanic...

Best regards,

-a-

[EricJ]

Getting the moisture out is an issue with cars, too.    People that have very short commutes, where the engine never quite gets up to temp, can have a similar issue.    This is one reason there's a recommended time limit on oil as well as an hour limit.   Condensation can get in the oil via the case interior and if it doesn't get boiled out it can cause issues.

 

[rbridges]

1 hour ago, Hank said:

Looks like it's from a milling machine . . . . Whatcha makin?

stir fried camshaft  

[GeeBee]

I have a Generac generator too. 40KW liquid cooled. The programmed exercise cycles are too short. I manually fire mine up once a month, put a load on it for two hours. I also only run 5-30 synthetic in it. If you do that you avoid, milky oil. 

[rbridges]

2 hours ago, GeeBee said:

I have a Generac generator too. 40KW liquid cooled. The programmed exercise cycles are too short. I manually fire mine up once a month, put a load on it for two hours. I also only run 5-30 synthetic in it. If you do that you avoid, milky oil. 

I saw some people mentioning running it under load.  I guess they also updated firmware that made the cycles shorter, and some people complained about that, too.  I did put synthetic 5w30.  Not sure what it comes with from the factory, synthetic or conventional.

[1964-M20E]

9 hours ago, rbridges said:

Not really mooney related, but kinda.  I built a house last year with a generac generator. I did the annual oil change yesterday. The generator does a monthly test run for 5 minutes or so. The oil was gold but somewhat opaque/milky. I knew it wasn't coolant but wondered why moisture would be in it. I googled and several people mentioned the same thing. They said it was from lack of runtime and not heating the oil enough to boil put moisture.  That's the first time I've ever seen that. Just an interesting observation. I see how that could be a problem for planes that sit around. 

I have the 15kW generac (for 15 years) but it runs for 15 minutes at full speed every week and no issues with the oil.  I think the new ones run at a lower speed and less time trying to be friendly to the neighbors.  However, appears not friendly to the generator.

[takair]

On the generac....since the run is simply to exercise the machine, I wonder if you couldn’t add a sump heater that adds a load and assists in bringing the oil up to temperature faster?

[GeeBee]

Generators need to run under load to properly warm up. Otherwise you are doing the same thing as a "ground run" with an airplane. The Generac programmed monthly run just keeps the fuel system primed and the battery charged. A real excercise requires a run under load.

 

[takair]

2 minutes ago, GeeBee said:

Generators need to run under load to properly warm up. Otherwise you are doing the same thing as a "ground run" with an airplane. The Generac programmed monthly run just keeps the fuel system primed and the battery charged. A real excercise requires a run under load.

 

So a sump heater may be nice for double duty?  Heating while providing a load?  Depending on the size of a generator, a sump heater may not even be enough of a load, but could get the oil to temp faster.

[RLCarter]

ALL engines suffer from short runs, they need to be brought up to operating temp and held there in order cook of condensation in the crankcase AND the exhaust not to mention getting the battery back to fully charged after the large drain of the starter. 

[Greg Ellis]

I have a 35kw generac at my house.  It is programmed to run every Saturday for 15 minutes.  Never have an issue with the oil or anything else.

[Awful_Charlie]

With the lock downs over here, I'd not driven the car since early September so went out today to remedy that. Blessed with an oil temperature sender, it was interesting to see that although the coolant was warmed up to normal after 15 mins / 25km, it took about double that to get the oil up to normal temp of 85-90 dC consistently.

Part way through the drive I could see the effect of the oil thermostat operating - the oil temperature would creep up a degree at a time, and then step back 7-8 dC to repeat, gradually increasing over a dozen or so cycles.

Surprised me how long it took to get the whole thing hot

Edited December 13, 2020 by Awful_Charlie
Typos

[jaylw314]

11 minutes ago, Awful_Charlie said:

With the lock downs over here, I'd not driven the car since early September so went out today to remedy that. Blessed with an oil temperature sender, it was interesting to see that although the coolant was warmed up to normal after 15 mins / 25km, it took about double that to get the oil up to normal temp of 85-90 dC consistently.

Part way through the drive I could see the effect of the oil thermostat operating - the oil temperature would creep up a degree at a time, and then step back 7-8 dC to repeat, gradually increasing over a dozen or so cycles.

Surprised me how long it took to get the whole thing hot

I was under the impression cars do not have an oil thermostat/vernatherm?  I thought the temp control was solely through the coolant radiator and thermostat?

[201Steve]

My cousin installs Generac and found the same problem. Naturally, I contributed to the conversation via airplane engines just as is happening here. 

[Browncbr1]

Open dipstick immediately after shut down every flight and let it all breath out while you put put it in the hangar and all.  I don’t close mine until steam stops coming out.  

[tmo]

13 hours ago, Awful_Charlie said:

With the lock downs over here, I'd not driven the car since early September so went out today to remedy that. Blessed with an oil temperature sender, it was interesting to see that although the coolant was warmed up to normal after 15 mins / 25km, it took about double that to get the oil up to normal temp of 85-90 dC consistently.

I'm pretty sure any non-antique car collects the data, not all present it. It can be read off CANBUS - I'm thinking something like this might be my winter project... I'll have to scale the "boost" so it goes up to 11 ;-)

Our daily driver (Skoda Fabia 1.2) doesn't even show coolant temp - just a blue light for "too cold" and (supposedly) a red one for "too hot". I guess with FADEC it "just works" and we're the 1% that like the info.

[carusoam]

Skoda Fabia 1.2

https://en.wikipedia.org/wiki/Škoda_Fabia
 

-a-