Cylinder failure early warning

[hais]

#5 on our IO550 is producing metal. 

The last oil change was 1.5 months ago. No metal. Engine has been running fine for 24 hours since. On runup this past weekend, EDM700 EGT and CHT for #5 went blank, and MP was lower than usual.

Mechanic took a first look, and suspected #5 was too lean. As part of troubleshooting, he changed oil and found metal. Final diagnose still pending.

I'm a bit shaken because damage appears to have progressed rapidly. I was expecting that metal would start showing up slowly in oil changes and give an early warning. 

Question: how could I have detected the problem early to mitigate risk of in flight failure?

The photo below shows metal found : is this enough to qualify as rapidly progressing failure?

The other question I have is: #2 always ran too cool at my typical power setting : WOT or 21MP, 2300rpm, and 11.4 gph. CHT is around 200. On the other hand, #5 was always the hottest around 300. Was this a sign of trouble?

The EDM700 photo shows the typical difference between #2 and #5 - taken back in February.

Unfortunately we can't record engine parameters. This is the G3X project that got stalled because of TC and FAA STC recognition issue. Is there another way to detect these issues? 

 

[N201MKTurbo]

Why do you think that metal came from #5 cylinder? 

Is that metal magnetic?

Have you looked in the cylinders? What do the spark plugs look like.

That’s a lot of metal, I can’t think of how a cylinder would do that.

[Guest]

I’ve never seen or heard of a cylinder making metal like that.  I’ve seen aluminum from a failed wrist pin end up in the filter, borescope revealed scoring on the cylinder wall so we knew exactly which cylinder.

I doubt that everything in that cup is metal.  Continental valve lifters do spall and fail as well.  There is an SB on it.  
 

For the OP call Pro Aero Engine for some guidance.

[Shadrach]

I can’t tell how big the orange container it but that’s a significant amount of metal either way.  
 

While not necessarily indicative of your current problem, I would not be at all happy with a 100° delta between cylinders. I would be reluctant to accept half of that under cruise conditions. I would suspect the instrument first. Barring that, if the delta was caused by a variance in power, the engine would likely be less than smooth.  That leaves a baffle/flow issue. All that being said, your engine was running very cool, so no issues with thermal stress. I would think a CHT ~200° might cause a problem with lead scavenging.

Look forward to learning the answer to this mystery.

[GeeBee]

200 is below minimum CHT

[mike_elliott]

Did the starter stay engaged after engine fired once by chance? That can make a lot of metal and why right after engine fire, check oil pressure and start power annunciating is off.

 

[Guest]

If you’ve ever rinsed old oil filter media into a container of varsol you’ll get a quite a pile of dirt, just like what’s in the orange container.  While it may follow your magnet around in circles, not all of it is large chunks of metal coming from a failing engine. Even a microscopic ferrous particle will be magnetic.

Ive got a TSIO520 I take care of that has more than 2100 hours, from time to time it’s made pencil lead sized ferrous particles.  Last week we replaced a cylinder on this engine, it had one spalled exhaust lifter which we replaced, the cam lobe was still fine.

I would borescope the cylinder looking for obvious signs of scoring and if there’s nothing obvious fill the engine with oil and fly it and check the filter next time.  Unless of course the engine is under warranty, then I’d discuss with the overhauler.

Clarence

[A64Pilot]

I have never seen that much metal out of an engine, that it wasn’t bad and almost all metal I’ve seen was shiny.

I believe what you have may be mostly carbon, but then I’ve never seen that much carbon either.

This was just in the oil not the filter?

I would not fly it until I found out what it is, and had a resolution. I can’t imagine a cylinder. I’ve seen broken rings make metal, but again it was shiny and of course very madnetic

[philiplane]

spalled lifters are the most common source of metallic flakes. Fortunately, they are relatively easy to replace, and not big money. You might have them checked next.

[hais]

Thank you all for your input, so in summary:

1. The metal may not be related to what appears to be power loss on #5 -> verify the source

2. Suspects: spark plugs, carbon, starter

3. 100F difference is not a good thing

4. Find out why #5 appears to have no power 

5. Don't lose confidence on oil filter inspection

[KSMooniac]

You should be looking in the cylinder with a borescope to see the valves and cylinder walls.

I also question the engine monitor readings. You might try testing the probes in some ice water and boiling water and see how they read. I can't believe you were flying with 200dF CHT in normal operation.

Good luck

Sent from my LM-V405 using Tapatalk

[carusoam]

Download the data off the JPI…

upload it to savvy…

Click the share button…

Post link here…

Then we can see what you were seeing…

And compare our IO550 and JPI experience with yours…

PP thoughts only, not a mechanic…

Best regards,

-a-

[A64Pilot]

To answer the initial question, cylinder failure indications, to me it’s always been sudden or slowly loss of compression, rarely oil leaks.

I’ve seen broken rings make some metal, but the sudden dead cylinder was the real indicator.

I’d find the source of that metal and worry about the engine monitor after the fact.

[thinwing]

Id take a look at the alternator drive also...

[hais]

Cylinder boroscope is showing damaged head and broken piston rings. Mechanic thinks it was caused by detonation. They haven't been able to root cause further until next week as they are tied up with other things. 

This puzzles me still : can detonation happen during ground ops? I'm leaning towards ruling out this happening in flight because I think I would have noticed it on the EDM. 

Too bad this EDM700 doesn't have a recording option. 

[A64Pilot]

Detonation doesn’t care if your flying or not, but is very unlikely to happen on the ground, unless your doing extended high power run-ups leaned out. I’ve never done that and doubt you did, I don’t know why anyone would.

Other things can cause damage, if there is no evidence of overheating then I’d maybe not suspect detonation, also rare but every blue moon an engine gets damaged by FOD.

[hais]

So they found broken piston rings, corroded lifter and sparring. Appears the damage was caused by corrosion. The airplane sat for a year before we bought it, that explains the corrosion.

A MSC gave the engine a clean bill of health 7 months ago. Been flown regularly after that, about 6 hours weekly on average. Sounds like an omission on the part of the MSC (they missed quite a few things). 

We are looking at 8 weeks down time to get replacement parts. 

[Ragsf15e]

11 minutes ago, hais said:

So they found broken piston rings, corroded lifter and sparring. Appears the damage was caused by corrosion. The airplane sat for a year before we bought it, that explains the corrosion.

A MSC gave the engine a clean bill of health 7 months ago. Been flown regularly after that, about 6 hours weekly on average. Sounds like an omission on the part of the MSC (they missed quite a few things). 

We are looking at 8 weeks down time to get replacement parts. 

Ouch.  With the lifters corroded, was the camshaft spalling?  That’s a common problem with airplanes that sit (and even some that don’t).  Lycoming engines seem to do that a lot with the cam up high.

There are quite a few folks on MS that have had these exact issues.

[Guest]

Let start off with the 550 series engine aren’t the best ones ever built. We just topped a 1200 hour IO 550 C in a Beech Baron, when we pulled the cylinders it still had great compression, but was randomly blowing oil out the breather tube.  Two cylinders had stuck compression rings and we found one spalled lifter, luckily with no camshaft distress.  I’ve seen 550’s in many different airframes stick rings, never seen it in a 520 series or a Lycoming.  The 550 is a problem child.

You can have good compression and still have internal issues that no mechanic will find, a borescope will not find a stuck ring, only cylinder removal will.   Unless you pull the valve train and the lifters your mechanic won’t know the face is spalling, the only sign is ferrous metal in the oil filter and removal is the only way to confirm it.  So unless your mechanic has X ray vision this is what we’re stuck with.

Clarence

 

[carusoam]

Back to the JPI 700 for a second….

Is it really not recording…?

Or you don’t have the wire connected to get the download….?

 

For a few dollars, you should be able to get the data out of that thing….

From the outside, it is hard to tell it is keeping data… until the wire is connected to it…. And a PC, and the JPI program…

 

It might even have the plug mounted on the panel in a cryptic way… looks like a small power supply socket with no label next to it…

I would be surprised that the data isn’t being recorded…

 

Unfortunately we don’t have a really good JPI guy around here…

Best regards,

-a-

[Fly Boomer]

14 minutes ago, carusoam said:

Back to the JPI 700 for a second….

Is it really not recording…?

Some EDM-700s don't have memory, and don't record (according to JPI support).

[hais]

On 6/2/2022 at 5:05 AM, carusoam said:

Back to the JPI 700 for a second….

Is it really not recording…?

Or you don’t have the wire connected to get the download….?

 

For a few dollars, you should be able to get the data out of that thing….

From the outside, it is hard to tell it is keeping data… until the wire is connected to it…. And a PC, and the JPI program…

 

It might even have the plug mounted on the panel in a cryptic way… looks like a small power supply socket with no label next to it…

I would be surprised that the data isn’t being recorded…

 

Unfortunately we don’t have a really good JPI guy around here…

Best regards,

-a-

I reached out to JPI when we bought this, and they walked me through the menu to check whether recording was enabled. Turned out it wasn't - strangely though, there's a download connector on the panel complete with a label. I concluded an older unit used to connect to the port. 

Didn't pursue that further since we settled for G3X EIS which is now gathering dust on the shelf waiting for TC to approve. 

[hais]

On 6/2/2022 at 3:49 AM, M20Doc said:

Let start off with the 550 series engine aren’t the best ones ever built. We just topped a 1200 hour IO 550 C in a Beech Baron, when we pulled the cylinders it still had great compression, but was randomly blowing oil out the breather tube.  Two cylinders had stuck compression rings and we found one spalled lifter, luckily with no camshaft distress.  I’ve seen 550’s in many different airframes stick rings, never seen it in a 520 series or a Lycoming.  The 550 is a problem child.

You can have good compression and still have internal issues that no mechanic will find, a borescope will not find a stuck ring, only cylinder removal will.   Unless you pull the valve train and the lifters your mechanic won’t know the face is spalling, the only sign is ferrous metal in the oil filter and removal is the only way to confirm it.  So unless your mechanic has X ray vision this is what we’re stuck with.

Clarence

 

Are stuck rings detectable in oil analysis? 

[hais]

On 6/2/2022 at 3:49 AM, M20Doc said:

Let start off with the 550 series engine aren’t the best ones ever built. We just topped a 1200 hour IO 550 C in a Beech Baron, when we pulled the cylinders it still had great compression, but was randomly blowing oil out the breather tube.  Two cylinders had stuck compression rings and we found one spalled lifter, luckily with no camshaft distress.  I’ve seen 550’s in many different airframes stick rings, never seen it in a 520 series or a Lycoming.  The 550 is a problem child.

You can have good compression and still have internal issues that no mechanic will find, a borescope will not find a stuck ring, only cylinder removal will.   Unless you pull the valve train and the lifters your mechanic won’t know the face is spalling, the only sign is ferrous metal in the oil filter and removal is the only way to confirm it.  So unless your mechanic has X ray vision this is what we’re stuck with.

Clarence

 

Another question: does oil seepage from the breather tube warrant investigation? 

[Guest]

46 minutes ago, hais said:

Are stuck rings detectable in oil analysis? 

Stuck rings lead to oil turning black right after an oil change.  The carbon in the blowby does the trick.  I don’t think oil analysis shows this.

Clarence