At what point does a sitting engine need certain precautions

SixPapaCharlie

SixPapaCharlie

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This is likely an elementary question, far beneath a lot of the high brow intelligent conversation I generally bring to the forum but..

The Cirrus is "supposed" to be reassembled in the next 2 weeks.
That will put it right around 3 months just sitting.

I would guess that is such a short period of time that it is not a factor but want to confirm.

Any things to do / check / etc?
 
I hear sometimes the oil starts to corrode the inside of the engine after a while but i'm not very knowledgeable on the topic. Just my two cents.
 
I'd probably pull the plugs, squirt some light engine oil the cylinders and do a good pre-oil before turning it over a few times by hand. Clear the oil from the cylinders and spin it with the starter until it builds good oil pressure. Put the plugs back in and fire it up. Fuel side of things, sample it, drain all the sumps well and if it doesn't look right or smell right, drain it all and put fresh in.

I'd also plan on doing an oil change after the test flights are done, as there is no telling what amount of crud and moisture has accumulated in it while the a/c was sitting idle.
 
You should have taken steps BEFORE it sat idle for such an extended period. Actually, I think Continental recommends preserving the engine if it's going to sit for a while. At this point the damage has been done. The oil has drained from providing it's anti-corrosion role.

Other than making sure things are topped up and tested, there's no procedure that's going to make this startup after a long wait better. Frankly, I disagree with most of Craig's advice. Throwing thin oils in the cylinders isn't going to accomplish anything useful and frankly if you don't know what you're doing, you can indeed damage things this way. Spinning the propeller at speed without starting the engine isn't doing anything either. If the oil pressure doesn't immediately come up on your 550, something is very wrong.

I do agree that an oil change at this point is a very good idea.
 
TK211X said:
I hear sometimes the oil starts to corrode the inside of the engine after a while but i'm not very knowledgeable on the topic. Just my two cents.
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Lots of variables. Location/climate. Inside or outside. Type of oil used. Type of engine.

I am not sure that there is any set answer.

One thing though: the oil itself doesn't start to corrode. The corrosion is usually from moisture inside the engine and may be worse if there are a lot of contaminants in the oil (IOW the oil had a lot of use before it sat for an extended period).
 
Ok, how long is too long for an engine to sit?
At what point does it become a concern.
 
SixPapaCharlie said:
Ok, how long is too long for an engine to sit?
At what point does it become a concern.
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Lots of variables there too. Climate, humidity, hangar, hours on the engine to develop a good varnish inside, hours on the oil before it sat?

Three months? Look for mouse nests, birds nests, start the thing, go fly. Get the oil warm and then change it. You'll be fine.
 
Continental says in one of their tip sheets that if you're in a coastal area that corrosion could start in 2-5 days. I know Lycoming used to recommend preserving the engine if it was going to sit for more than a week.

Fearless is right, it's not the stuff IN THE OIL that's really the problem It's sitting there with the oil in the sump pretty harmlessly. It's the fact that the various internal surfaces are protected form corrosion by the residual sheen of oil. The longer the engine sit, the more of that drains off and exposes the metal to damage.
 
FlyingIsGood said:
Pull the chute.
Click to expand...

this, like farting and the metal landing calculator, never gets old.








{no, YOU grow up!}



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anyways, I am no expert for sure, but I don't think you should worry too much about it in this case. If an oil change sets your mind at ease, go for it. I think the problems start when you let a plane sit for a long time, then maybe fire it up but not get the temps up to operating range then shut it down and let it sit again, repeat, repeat.....then you should be concerned. now I'll be prepared for the pros to shoot my theory down.
 
Take a couple laps around the pattern, change the oil,cut the filter, if all is well, fly the **** out of it.
 
If there were a right answer to your question, there wouldn't be so much discussion about it, so take everything you read here with some skepticism.

The oil seems to drain off parts inside after a couple weeks. Using something like camguard supposedly helps it protect another week or two from disuse.

As for how long until corrosion starts, there are a ton of factors that go into it. You can find some planes in Texas that sat a few years, and run regularly after that with no issues until TBO. Then there are others that were down just a month or two that can be corroded to hell. What really gets to you is when two planes sitting next to each other are flown/treated the same way, and one has internal corrosion issues, and the other is fine.

In a typical environment (not super humid or dry), I would say if you let it sit a month while down for maintenance, it isn't the end of the world, but I sure wouldn't do it regularly. I get real antsy if I can't fly at least once every two weeks, and thankfully that is very rare. I try and get out at least every week. My plane was down 3-4 weeks this year for maintenance and I was itching like a heroin addict. Any longer than a month, and put in some desiccant plugs or take other active steps to keep it dry in there.
 
There's no one answer to your question. If the engine was in good shape the last time it flew, then you're probably gonna be ok. The right way to maintain an engine in flyable storage is to first fly it long enough to ensure that has been at operating temps for awhile, then change the oil and pull the plugs and replace them with desiccant plugs.

To "pickle" an engine for long-term is different. And, not something I'd do if I were planning on fly behind it in a few weeks.
 
.....when I self-grounded, I pickled my engine for a few weeks per Lycoming's Service Bulletin - it's NOT a major undertaking.
 
I would bet that 98% of all airplanes have inactive periods of three months or more without any preparation, and still fire up and run just fine for years afterward and for many other long periods of sitting. If it was a huge problem we'd have thousands of accidents every year due to corroded engines and a bunch of regulations governing engine preservation.
 
I would think they would throw free oil change in the deal considering. Otherwise I wouldn't worry about it. I leave continentals sit for long periods and never have any problem.
 
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