Rust and corrosion in cylinders during prebuy

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4RNB

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4RNB
Prebuy was done today.
Plane has flown maybe 15 hours in 2 years.
5 of 6 bottom spark plugs had oil. All need replacement.
Cold compressions 72-76.
Fair amount of oil on one side of engine, no clear source, some was present around filler neck so could be a spill.
‘There is some rust and pitting in the cylinders”
“Camshaft condition unknown due to lack of recent activity”
“Cylinders look very good and we were able to see 3 lobes through the oil filler neck and those looked good”

How would you handle this report and potential purchase?
 
welcome to the junk that is the market. Overpriced as all get out too. For my part I am biased towards high time engines (they're all largely calendar timed out anyways) with a demonstrated 24 month recency amortization of 100 hours of better. The sitters don't strike my fancy, regardless of the "low time".

I bought an airplane with 2000smoh and flew it with little ill effect for a year, putting almost 300 hours. It was the 1100smoh one that betrayed me (10 years later), but I digress.

It's a crapshoot. Low ball the guy, I wouldn't incur the price risk. I don't mind inheriting other people's problem (and they are unloading a problem, I don't know why people act like they're not; it's rather stipulated if we're all being adults in a negotiaton), but I'm not paying them a premium for the privilege. As a seller, I've taken my loss as well under the same guise of good for the goose good for the gander. But I'm weirdly straight forward like that, most sellers are emotional clowns.
 
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4RNB said:
Prebuy was done today.
Plane has flown maybe 15 hours in 2 years.
5 of 6 bottom spark plugs had oil. All need replacement.
Cold compressions 72-76.
Fair amount of oil on one side of engine, no clear source, some was present around filler neck so could be a spill.
hindsight2020 said:
welcome to the junk that is the market. Overpriced as all get out too. For my part I am biased towards high time engines (they're all largely calendar timed out anyways) with a demonstrated 24 month recency amortization of 100 hours of better. The sitters don't strike my fancy, regardless of the "low time".

I bought an airplane with 2000smoh and flew it with little ill effect for a year, putting almost 300 hours. It was the 1100smoh one that betrayed me (10 years later), but I digress.

It's a crapshoot. Low ball the guy, I wouldn't incur the price risk. I don't mind inheriting other people's problem (and they are unloading a problem, I don't know why people act like they're not; it's rather stipulated if we're all being adults in a negotiaton), but I'm not paying them a premium for the privilege. As a seller, I've taken my loss as well under the same guise of good for the goose good for the gander. But I'm weirdly straight forward like that, most sellers are emotional clowns.
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‘There is some rust and pitting in the cylinders”
“Camshaft condition unknown due to lack of recent activity”
“Cylinders look very good and we were able to see 3 lobes through the oil filler neck and those looked good”

How would you handle this report and potential purchase?
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To check the cam; on some Lycoming, pull two back cylinders, if they let you (probably not, but worth a try) a cam worn enough will drastically effect power.
 
Dave Palacios said:
To check the cam; on some Lycoming, pull two back cylinders, if they let you (probably not, but worth a try) a cam worn enough will drastically effect power.
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This one sounds more like a Continental. Viewing the camshaft through the filler neck is a hint, as is the "oil in 5 of the 6 bottom plugs." Small Continentals were famous for oily bottom plugs after a runup.

"Rust and pitting in cylinders" implies ground-running without flying. An engine-killer. I'd bet that pulling a mag just might find some rusty gears in the accessory case.
 
What climate is this bird located?

Have your A&P explain the “some rust and pitting in cylinders” and “cylinders look very good” dichotomy. He/she may have seen a lot and might have a good feel for these things. Or not. Hard to tell from these seats, you’re on the field playing ball, we’re just watching.

Use the report to your advantage in negotiating a good deal.
 
Lycoming
Humid climate at least on this day. We were sweating in morning soon of unconditioned hangar.
Family that used to live in the area said it was a dry heat area though
Not in report, but mechanic said it was one of the better engines he’d seen

Blow by oil in old plugs in setting of good cold compressions for a plane that has sat , not sure what to make of it. Plugs old

For a price adjustment, the key to me is to try and guess risk of bad engine. If chance of needing new or rebuild is 20%, need that amount of adjustnent
 
Savvy Aviation has a (free?) engine boroscope service that will advise you on your cylinders in exchange for the photos and follow up. They want to build a database of boroscope images, problems and resolutions.

Call them and ask about it.
 
4RNB said:
… guess risk of bad engine. If chance of needing new or rebuild is 20%, need that amount of adjustnent
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Every engine has a 100% chance of rebuild, due to time or condition. The only two questions two answer are:

1. Does my budget allow me to buy this plane today and be able to replace the engine tomorrow?

2. Is the total package worth what you think it’s worth?
 
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if you like the bird make an that is worth you taking a risk.

that engine could be perfectly fine or it may decide it's done in only a few hours. Could be all the cylinders are bad, they are easily replaced. Heck even if it looked perfect, you have the same problem.


worse that can happen is the guy says no
 
Look at the lifter, not the cam. Looks “crystalline” to me. One valve base looks asymmetric.

I suppose you guys cut and looked at the oil filter? I wouldn’t think it had many hours on it, so might not be a useful indicator.

I have no standing to out-opinion your A&P, but just budget for stuff, including downtime, delays, and spousal disappointment, and you should have no surprises.
 
Is this a plane flip, and you're an A&P? If so, then you can figure out the cost to repair the engine.

Is this your first and last plane?

If the latter, then take a pass. There's always another plane. It's not only what's been identified in the pre buy, but all the other what not that you're not aware of yet. A plane that has sat long enough to give you these pictures has a lot more issues that will pop up in short order.
 
WDD said:
Is this a plane flip, and you're an A&P? If so, then you can figure out the cost to repair the engine.

Is this your first and last plane?

If the latter, then take a pass. There's always another plane. It's not only what's been identified in the pre buy, but all the other what not that you're not aware of yet. A plane that has sat long enough to give you these pictures has a lot more issues that will pop up in short order.
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Not a flip, not an AP
My first plane was my last plane until I sat in and flew this model (and I fit in it). This offers significant cruise speed benefit, maybe more room, amongst other things.
Might now be my last plane, can't picture a set of circumstances for wanting or needing more performance. Cruises 170kt
 
If the plane itself was in decent condition, including avionics, I would just treat it as runout engine and subtract the price of a new (or reman) engine in my offer.
 
JOhnH said:
If the plane itself was in decent condition, including avionics, I would just treat it as runout engine and subtract the price of a new (or reman) engine in my offer.
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I went 40K off previous price, waiting to hear.
 
4RNB said:
I went 40K off previous price, waiting to hear.
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Do you think that's enough? A friend recently put a new IO550 in his A36 and I believe it came to around $80k. I'm not sure if he had anything else done at the same time but all he talked about was the engine.
edit: Also, he had to wait many months for delivery.
 
JOhnH said:
Do you think that's enough? A friend recently put a new IO550 in his A36 and I believe it came to around $80k. I'm not sure if he had anything else done at the same time but all he talked about was the engine.
edit: Also, he had to wait many months for delivery.
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I don't know. I'm thinking of this as guessing the chance of engine replacement being needed the next 100 hours. Absent data, this gets me close to 50% of new.
 
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