Metal in Engine Help

[meritflyer]

So, I have a pre-buy done today on a Turbo Arrow IV that I am considering buying and here is the mechanic's biggest concern.

In March '09, the turbo failed in flight. One of the turbo blades completely came apart and became a pile of metal dust.

The plane was landed uneventfully and taken in for the service to repair.

The plane received a new turbo after the cylinder walls, compressions, manifolds, and piston crowns were all inspected via boroscope with no defects. The turbo was replaced.

Now, the fun part.

The mechanic that put the new turbo in advises the oil needs to be changed every 5 hours for atleast 4 changes. The first three yield non-magnetic metal (not a good sign I presume) although he notes the metal is a result of the turbocharger failure.

In the last 10 hours, it's been clean including today when the mechanic cut open the filter during the pre-buy. The concern is, that there are metal parts floating around in the engine and may not be able to be detected and could cause piston and crankshaft failures (hope I said that right).

The owner is confident that it's not an issue as the metal in the filter was a result of the blade. The mechanics are being cautious but suggesting that it's probably not an issue but there's no real way to tell. They are going to pull the oil suction screen tomorrow for another 'gut' check but all in all, they said there's really no way to tell immediately if there's metal in the engine.

I need your input on this, folks! What do I do?

(I also posted this in Tech Talk. Can you Mods please leave it here too?)

[Mariano]

Originally Posted by meritflyer

So, I have a pre-buy done today on a Turbo Arrow IV that I am considering buying and here is the mechanic's biggest concern.

In March '09, the turbo failed in flight. One of the turbo blades completely came apart and became a pile of metal dust.

The plane was landed uneventfully and taken in for the service to repair.

The plane received a new turbo after the cylinder walls, compressions, manifolds, and piston crowns were all inspected via boroscope with no defects. The turbo was replaced.

Now, the fun part.

The mechanic that put the new turbo in advises the oil needs to be changed every 5 hours for at least 4 changes. The first three yield non-magnetic metal (not a good sign I presume) although he notes the metal is a result of the turbocharger failure.

In the last 10 hours, it's been clean including today when the mechanic cut open the filter during the pre-buy. The concern is, that there are metal parts floating around in the engine and may not be able to be detected and could cause piston and crankshaft failures (hope I said that right).

The owner is confident that it's not an issue as the metal in the filter was a result of the blade. The mechanics are being cautious but suggesting that it's probably not an issue but there's no real way to tell. They are going to pull the oil suction screen tomorrow for another 'gut' check but all in all, they said there's really no way to tell immediately if there's metal in the engine.

I need your input on this, folks! What do I do?

(I also posted this in Tech Talk. Can you Mods please leave it here too?)

I'm not a mechanic yet. However if the engine ingested metal particles and they are floating around, I think that it could lead to failure or even catastrophic failure. All those non-magnetic particles are floating with the oil in the lubrication system and causing damage/wear on bearings which have very small tolerances.

You'll get a better answer from the guys that are already mechanics with experience. But I think that at least the engine should be taken apart and carefully inspected for damage and then cleaned and reassembled.

I'm still in AP school so perhaps all I told you above is BS. But I thought I'll give it a try and help.

[deadstick]

I believe oil analysis will tell you where the metal is coming from. The rings, cylinders, turbo blades, bearings -- all (I believe) have unique compositions and can be identified. Wasn't the system flushed after the turbo puked?

[proheff]

I would suggest using the Blackstone oil analysis. This company gives a very easy to understand report; not just numbers.
Another thing it is a buyers market so be picky.

[sefro]

The other question is how much metal are you finding in the oil filter.

[OldTownPilot]

I saw an oil filter once that I could use as a mirror to comb my hair. Thankfully that was not on one of our airplanes, but impressive none the less.

[Roger, Roger]

Originally Posted by OldTownPilot

I saw an oil filter once that I could use as a mirror to comb my hair. Thankfully that was not on one of our airplanes, but impressive none the less.

*Shiver*

[sefro]

Originally Posted by Roger, Roger

*Shiver*

I see $$$$$