engine test help

texasag93

texasag93

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texasag93
I am looking at a little Piper 140 that has 500 hours on it.

I want to know what I should have tested on it other than compression.

The man selling it is the club A&P, so I trust him in that he has not done anything (that I know of) to screw us.

I was thinking about offering to do an oil analysis and then run it for 20 hours or so (and pay him for that time) and then do another oil analysis.

Would that do anything or what other things can I do.

He bought this airplane to fix it up to sell.

Thanks,

Brian
 
texasag93 said:
I am looking at a little Piper 140 that has 500 hours on it.

I want to know what I should have tested on it other than compression.

The man selling it is the club A&P, so I trust him in that he has not done anything (that I know of) to screw us.

I was thinking about offering to do an oil analysis and then run it for 20 hours or so (and pay him for that time) and then do another oil analysis.

Would that do anything or what other things can I do.

He bought this airplane to fix it up to sell.

Thanks,

Brian
Click to expand...
I wouldn't buy an airplane from an A&P without a thorough going over (e.g. annual inspection) from a different, unrelated AI familiar with the specific make/model. And 20 hrs followed by oil analysis isn't going to prove a lot. You might do better to have the cylinders borescoped (fairly inexpensive). No matter what you do, expect to spend up to 10% of the purchase price on maintenance during the first year as things tend to get missed no matter how detailed the pre-buy is.
 
Borescope inspection. Oil analysis.
 
gismo said:
I wouldn't buy an airplane from an A&P without a thorough going over (e.g. annual inspection) from a different, unrelated AI familiar with the specific make/model. ....
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Agreed.... There are one too many A&P's out there using the excuse of being a FAA certified mechanic to create a air of superiority...:yes::(..

Ymmv..
 
Be sure your a&p inspects the oil filter. May save you a lot of money and trouble.
 
Check if the 500 hr mag inspection has been done.

Check for corrosion under the fuel tanks.

check for corrosion under the battery box.
 
You are not going to prove anything with the oil analysis without a TREND. You cannot get that with just two samples. If it makes you feel better than have at it. Big thing....get a pre-buy from a mech. and not the one selling the plane.
 
flyingmoose said:
You are not going to prove anything with the oil analysis without a TREND. You cannot get that with just two samples. If it makes you feel better than have at it. Big thing....get a pre-buy from a mech. and not the one selling the plane.
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I respectfully disagree......

If you do a one time oil analysis and the report comes back with sky high, iron, or tin, or lead, or chrome, or any other tested element then you can safely assume the motor is eating itself up.....

Matt-
CMEL CFI A&P IA



As a licenced FAA mechanic you should try to give better and more accurate answers sir... IMHO.
 
Get a different set of eyes on it. Just did an annual on a newly purchased aircraft that didn't have a prebuy done. The sellers mechanic said it was in good shape and if you ever want to sell it, let me know, I'll buy it. Hmmmm... The new owner got lucky, nothing life threatening found, but a few squawks that definetly didn't happen overnight and arent gonna be cheap...

bartmc said:
Hire an a&p
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gismo said:
I wouldn't buy an airplane from an A&P without a thorough going over (e.g. annual inspection) from a different, unrelated AI familiar with the specific make/model. And 20 hrs followed by oil analysis isn't going to prove a lot. You might do better to have the cylinders borescoped (fairly inexpensive). No matter what you do, expect to spend up to 10% of the purchase price on maintenance during the first year as things tend to get missed no matter how detailed the pre-buy is.
Click to expand...

Skylane81E said:
Get your own mechanic on the job
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kgruber said:
Check if the 500 hr mag inspection has been done.

Check for corrosion under the fuel tanks.

check for corrosion under the battery box.
Click to expand...
 
N801BH said:
I respectfully disagree......

If you do a one time oil analysis and the report comes back with sky high, iron, or tin, or lead, or chrome, or any other tested element then you can safely assume the motor is eating itself up.....

Matt-
CMEL CFI A&P IA



As a licenced FAA mechanic you should try to give better and more accurate answers sir... IMHO.
Click to expand...

Well, I happen to agree with Matt.
 
VanDy said:
Get a different set of eyes on it. Just did an annual on a newly purchased aircraft that didn't have a prebuy done. The sellers mechanic said it was in good shape and if you ever want to sell it, let me know, I'll buy it. Hmmmm... The new owner got lucky, nothing life threatening found, but a few squawks that definetly didn't happen overnight and arent gonna be cheap...
Click to expand...

When was the last time you heard a seller say "This airplane is a complete piece of **** and I never want to see it again." ;)
 
Ted DuPuis said:
When was the last time you heard a seller say "This airplane is a complete piece of **** and I never want to see it again." ;)
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This was from the airplanes prior mechanic, so it had to be true!!:rolleyes:
 
To throw my suggestion in, I'd agree with wanting an A&P on my side to look it over for general condition, including cutting open the filter. Put me in the camp of not bothering with oil analysis, but for $20 it's cheap enough that it's not a big hardship if you want to do it. You really need trends, though.

Also, look at a detailed history of the engine. Who did the overhaul? What were the criteria used? I can't tell you how many people I've seen buy a plane with a "good mid-time" engine only to find out that the engine was overhauled by Monkey Joe in a barn. The engine leaks like crazy, the cylinders have 8,000 hours on them, etc...
 
You are also assuming that the owner didn't change the oil and filter five minutes before you showed up and collected your sample.... Maybe I'm a cynic and don't trust anybody, but I assume that most people are out to protect their bottom dollar.

N801BH said:
I respectfully disagree......

If you do a one time oil analysis and the report comes back with sky high, iron, or tin, or lead, or chrome, or any other tested element then you can safely assume the motor is eating itself up.....

Matt-
CMEL CFI A&P IA



As a licenced FAA mechanic you should try to give better and more accurate answers sir... IMHO.
Click to expand...
 
N801BH said:
I respectfully disagree.......
Click to expand...
YOu can.

N801BH said:
As a licenced FAA mechanic you should try to give better and more accurate answers sir... IMHO.
Click to expand...

Well as an a&p and IA and aircraft maintenance business owner, I always give the best advice I can. If you think my answers are not accurate...sorry! I stand by them. I said if you want to do it...have at it its cheap enough. Usually without a trend you will not be able to make a good assesment as to the condition of the engine.
 
VanDy said:
You are also assuming that the owner didn't change the oil and filter five minutes before you showed up and collected your sample.... Maybe I'm a cynic and don't trust anybody, but I assume that most people are out to protect their bottom dollar.
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Correct,

But Ted also makes a good point, it is cheap enough to just do it. Who knows maybe you will get "lucky" and find a problem.

I always do a prebuy with the goal of proving to the buyer they don't want the plane, so if I fail, bully!
 
Skylane81E said:
But Ted also makes a good point, it is cheap enough to just do it. Who knows maybe you will get "lucky" and find a problem.
Click to expand...

Well, my point was more if you want to, have at it. Most likely you will end up coming to a determination that isn't accurate from it, though. So I wouldn't bother. I also wouldn't tell someone not to if they had their heart set on it. It's not a big deal one way or the other, so folks shouldn't get riled up about it. Lots of other things one should be looking at on an engine.
 
Ted DuPuis said:
Well, my point was more if you want to, have at it. Most likely you will end up coming to a determination that isn't accurate from it, though. So I wouldn't bother. I also wouldn't tell someone not to if they had their heart set on it. It's not a big deal one way or the other, so folks shouldn't get riled up about it. Lots of other things one should be looking at on an engine.
Click to expand...

Roger,

How about the most valid reason to do one?


What if you buy it?
 
Skylane81E said:
Roger,

How about the most valid reason to do one?


What if you buy it?
Click to expand...

If you do buy it and intend on doing oil samples, then you've got e first step in your trending. Although the caveat there is you don't know how they've been running the engine vs how you will, the hours probably won't be right at oil changen etc. So I think there's limited benefit there, but they can exist.

If you get some high samples, it might warrant further investigation, but it could also mean nothing and you lack a trend to go by. If you're feeling iffy about the engine (in which case you should probably just walk away) it might convince you to walk away.

If the previous owners have been taking samples, then you'll have the latest sample for trending.
 
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