Engines go bad if they sit?

[Vik]

While looking for a plane to buy I ran across a plane yesterday that has only been flown 10 hours in the past 3 years. Yes, sad but true, only TEN hours in the past 3 years.

What does that do to engine life and to the engine? Its a twin with about 1125 hours SMOH per side.

Looking for insights into how to evaluate this.

 

[Traumahawk]

My .02 plus a couple bucks might get you coffee @ signature....oh wait, it's free....so keep that in mind

Rust never sleeps.....

What part of the country is it in?
Both major engine manufacturers recommend the engine being run at LEAST an hour a month...however corrosion can be found in an engine as little as 2 days after a shutdown.

10 hours in 3 years....definately time for an oil change, hopefully it has had them at the time intervals whether it ran or not.

The best thing to do is pull a jug on each side and take a look. After that amount of idle time it's definately a must if you're going to fly/buy the plane...

If it is going to fly, do an oil change, probably best to get some new fuel in it too. Very thorough runup. Pay close attention to static rpm...Make sure the operating temps get up high enough during the flight....at least an hour.

Afterward pull the cowl and check for oil leaks. Watch oil consumption very closely and do a compression check after a few hours, that way any crap in the cylinders has worked itself out...
Change the oil again soon after...Check the screen/filter for metal.....

Usually that amount of idle time just isn't good news.....

T-Hawk

 

[TDTURBO]

Don't touch it unless run out engine reserves are priced into the sale. Even if the engines are 0 time, 10 years is a lot of down time. Unless you tear it down completely, it is hard to tell what damage took place and if you're going to do that, you might as well overhaul the engines. There are exeptions but very few.

 

[regionalcap]

He said it was 3 years not 10.

 

[Dragonbravo]

What type airplane? Is it hangared or tied down? What is the current compression? Where is it at now? Why are you buying it, what do you plan to do with it, how long do you plan to keep it? I bought a C-120 that had flown 100 hrs in 10 years. It was WELL below book value because it had a "weak engine", Duh! But I bought it with the intent of restoring it. I put 100 hours on it and the compression came up. So just because it has sat dosen't mean its a giant rustsicle. But it is something to consider. And even if the engine does pass muster now, it's life span has definately been shortened. By 120 did not make it to TBO. But again, I bought it with that in mind, knowing that it would get overhauled eventually. What other features are there? Are all the AD's complied with? Has it been bent? Are the avionics any good? If you like everything about it except the engine, then I'd still look at it. If it needs an intierior and paint, new radios, etc. and you aren't looking to put a lot of time and $$ money into it. Then keep walking.

 

[TDTURBO]

He said it was 3 years not 10.

Sorry bout dat, I read it to fast.

It still needs a close and cautious look over.

 

[Super 80]

Well you have double the trouble with a twin. If there is any corrosion, just turning it over is going to circulate it throughout the engine. The greatest danger is in the bearings. Next would be the rings. Being a twin means it's naturally dangerous. They aren't called doctor killers for no reason. I'd hate to see you just try to run it into shape and have one go out on a takeoff when you're generating the most rpm, power and heat.

Best advice is play it safe. If you can't buy it for a discounted price so when you add in a double engine rebuild that it's still an attractive price, then walk away. If this has has really been sitting that long, depending on the conditions it was kept under, you might want to look for all kinds of oddities. Many an aircraft has been found with various critters' nests fouling up rigging and other vital functions.

I don't know the particulars, and there's a lot of variables, but if it doesn't smell right, (and assuming you're not "in love" with the plane) walking away might motivate the seller to lower his price to something that makes it attractive. After all, he's the one that let it set, he ought to pay the price not you.

I also have to ask why he doesn't get it in good running. Is he afraid to take his family up in it? Remember, it's a collection of various moving parts put together in a way that's designed to come apart. As a mechanic told me: "If it has tits or tires it will give you trouble."

 

[L.Skywalker]

It's my uneducated understanding that Continentals suffer from neglect more than Lycoming. Anyone know better?

 

[Wankel7]

I have also heard that it is bad if the engine was run up on the ground and not flown. Reason being that running on the ground does not get the oil to a temp where the moisture in the oil will drain out of the case. Only flying the airplane will get the oil to a temp where this occurs.

Wankel

 

[moving2vegas]

sitting too long

Get a very qualified mechanic to look at the plane as a whole. Every pilot, myself included, thinks they know engines. Wrong. My employer just purchased a 40 year old twin with 2800 TT and engines that hadn't been flown in 3 years. The previous owner was the original buyer and he babied the plane from day one. Always pulled the props through by hand, started it every few weeks, changed the oil regular and preformed 100 hrs well below requirements. The a/c was pristine, but the CP was concerned about buying the old plane because of low overall use and the sitting engines. Our mechanic went through it and said if the CP didn't buy it he would (it was that nice) and tens-of-thousands below book. Yes, old planes/engines can be nightmares. But they can be goldmines also. Consult a mechanic.

 

[Vik]

Thanks for the replies everyone!

Yes, the plane is cheap enough that should the engines fail the pre-buy, I will just get the plane for even cheaper.

Right now I am assuming the engines are dead, even though they are at 1,100 hrs SMOH (2000 hr TBO).

I am having a specialist with this type of airplane do a pre-buy on it. He is going to do compression tests, oil analysis and has a whole game plan setup.

The plane is cheap and my offer is cheaper. I plan to refurb it and fly it around, build multi experience and enjoy it.

Thanks again for the input.

 

[pilotjc]

t

 

[avbug]

Dragonbravo,

Sometimes I wish the requirement for a compression check would go away. Pilots hear about them and think they mean something, when in fact they mean nearly nothing. That your compression went up says nothing about being a "rustsickle," or otherwise. It only lends you a false sense of security that the engine hasn't developed rust. Rest assured, it has.

An engine oil analysis is certainly in order. You should be a whole lot more interested in that than a compression test.

Always pulled the props through by hand, started it every few weeks, changed the oil regular

Of those three things, only one is benificial. Pulling through by hand is damaging most definitely not benificial (removes oil from cylinder walls and adds unnecessary wear, and reduces protective films during the actual start proceedure). Starting the engine every few weeks is dandy...so long as it's run to operating temperature and kept there long enoug. Also, every few weeks isn't really enough.

Right now I am assuming the engines are dead, even though they are at 1,100 hrs SMOH (2000 hr TBO).

The 2,000 hour TBO doesn't really apply to anything but a first-run engine, or a factory reman. Especially due to the varying nature of what constitutes an "overhaul" or even a major overhaul, don't ever count on or project making "TBO" on an overhauled engine, excepting a reman.

It's my uneducated understanding that Continentals suffer from neglect more than Lycoming. Anyone know better?

Yes...that's wrong. All engines suffer from neglect. All suffer equally, all else being equal. Neglect a dozen different engines in the same manner, and note that they all face the same challenges.

Other than simply looking at the engine, additional issues must be addressed. It's unlikely that if the airplane hasn't been flown regularly, it hasn't been kept up with maintenance, including airworthiness directioves, applicable service bulletins, inspections, etc. Further, seals harden and crack, hoses must be replaced. Sitting is very hard on an airplane; much, much harder than flying. Good luck!

 

[low-n-slow]

Can damage be done to a turbine engine from sitting idle for long periods of time also?

 

[Catbird]

Piston A/C- Corrosion pitting lifter surfaces. Leads to expensive problems later. Requires a knowledgeable mechanic to inspect. Rebuilt doesn't necessarily mean rebuilt in the A/C engine business.