My IO-360A3B6 is making metal (and I’m going to be losing coins)

[bradp]

Hey all,

Lynn found a significant amount of metal in the filter during annual.  This is some sort of acute event since last oil change about 25 hrs ago.   It’s been running fine.  Compressions good.  Regardless, Lynn and Ron have been discussing and we talked it over today.  He’s going to pull #3 and scope the cam as a first step.   Engine has 1050 hrs since factory rebuild in 2005 when it was converted to an A3B6 (no dual mag). 
 

The case will certainly need to be split.  Then the decision point seems to be IRAN or OH, and if IRAN whether I ask Lynn to build up the engine in house with sent-out components vs Jewell etc do the work.    Lead time seems to be an issue in pandemic world.  
 

If it’s a clearly spalled cam, it simplifies the decision. If the cam looks awful, I’ll likely go down the simple IRAN route.  If it’s not the cam, are we down the rabbit hole with journal bearings, fretting etc and looking at IRAN still or just do the overhaul for the core?  
 

Ron mentioned he thought the metal didn’t look like typical for cam spalling- more shredded, but I don’t have the experience and can’t tell much about the character of the metal from the picture I have.  

 

The metal is ferrous (ie magnetic). 
 

Presuming we keep the plane, I’m thinking IRAN the mid time engine if it looks like the top is the root cause.  
 

If I were to think about selling it (and this conversation has come up given growing family), I’d think I’d overhaul / factory rebuild it do maximize the SMOH recoup (whatever that may be), marketability.  
 

If this is a bad cam… DLC lifters? 

[A64Pilot]

See if the metal sticks to a magnet, otherwise I think you need to wait until you inspect the cam before you make a decision. If it’s doesn’t stick to a magnet then of course it’s not likely cam/ lifters.

People seem to think there is a huge price difference between IRAN and overhaul, and often there isn’t. It depends on how much you decide to do on either.

I usually go overboard as I believe it’s pay me now or pay me later and is there ever a better time to inspect when the parts are laying on the table?

An overhaul can be as simple, as disassemble, clean,  inspect, and reassemble. It’s not hard to find several links to the definition of an overhaul.

If I were doing an IRAN, personally I’d at least inspect everything to the best of my ability and replace any parts that aren’t serviceable.

I would hope that anyone who does an IRAN would follow Lycomings SB for parts required or be replaced whenever an engine is taken apart, especially on one that’s making metal.

Being mid time it’s tough to through out the recommendation to overhaul without knowing what you have, if you were at or close to TBO I’d say overhaul as I believe a low time engine adds value to the airplane.

[bradp]

Thanks @A64Pilot  - that’s why I’m thinking it’s a good idea that Lynn is pulling a cylinder and taking a look at the cam.  It will set at least an expectation for findings and which path to se down-  OH vs IRAN.  
 

The material in the filter is magnetic. 

[lotsofgadgets]

Brad, I've got bad news for you....  

I am in the same boat.  Back in March I pulled a cylinder after it was determined that the #4 exhaust valve was sticking.  We found the cam and lifters were not just worn, but shot!  It's taken several months, my wallet is MUCH lighter, but they just ran the overhauled engine on Monday.  I have several writeups and pictures posted on JustPlaneRadio.com.  I also posted a video this morning of the first engine run if you want to see what a fresh overhauled IO-360-A3B6D will look and sound like.

 

[jetdriven]

1 hour ago, bradp said:

Hey all,

Lynn found a significant amount of metal in the filter during annual.  This is some sort of acute event since last oil change about 25 hrs ago.   It’s been running fine.  Compressions good.  Regardless, Lynn and Ron have been discussing and we talked it over today.  He’s going to pull #3 and scope the cam as a first step.   Engine has 1050 hrs since factory rebuild in 2005 when it was converted to an A3B6 (no dual mag). 
 

The case will certainly need to be split.  Then the decision point seems to be IRAN or OH, and if IRAN whether I ask Lynn to build up the engine in house with sent-out components vs Jewell etc do the work.    Lead time seems to be an issue in pandemic world.  
 

If it’s a clearly spalled cam, it simplifies the decision. If the cam looks awful, I’ll likely go down the simple IRAN route.  If it’s not the cam, are we down the rabbit hole with journal bearings, fretting etc and looking at IRAN still or just do the overhaul for the core?  
 

Ron mentioned he thought the metal didn’t look like typical for cam spalling- more shredded, but I don’t have the experience and can’t tell much about the character of the metal from the picture I have.  

 

The metal is ferrous (ie magnetic). 
 

Presuming we keep the plane, I’m thinking IRAN the mid time engine if it looks like the top is the root cause.  
 

If I were to think about selling it (and this conversation has come up given growing family), I’d think I’d overhaul / factory rebuild it do maximize the SMOH recoup (whatever that may be), marketability.  
 

If this is a bad cam… DLC lifters? 

I wouldn’t put anything other than DLC or roller lifters in an engine these days. But that certainly looks like  lifter fragments. 
It could be Cascades to embed it metal in the bearings, score crank, trash oil pump, scored cylinders. That metal does a number.
To top it all off, new cylinders are 6 to 9 months out lead time. And if you call triad for example, and say hey I want to send my engine to you for an overhaul you’re not going to get it for nine months.

[EricJ]

Proceed carefully, or you may wind up spending money unnecessarily.

My IO-360-A3B6D started making a significant amount of metal a few years ago.   Since it was under the max amount specified in Lycoming's guidelines (which is a huge amount), I let it go for a bit.   The shop that had done the last rebuild and Lycoming both had reps at the local IA seminar, and when I talked to each of them separately about it they both said to just keep running it as usual and monitor it.   It kept making a lot of metal for a few oil changes, and then started tapering off.   It was running fine, made good compression and power, so I wasn't too worried about it and figured whatever was wearing was clearancing itself or something.

Then my prop governor started acting up, got really slow on runup, and then on the next flight's runup got much slower.   That was unusual, so I aborted the flight and we figured out that my prop governor was toast.    I took it to the local prop shop and they said essentially all of the internals were worn so badly that it would cost as much to rebuild it as to buy a new one, so I bought a new one.

I've seen very little metal in the oil since then, and that was quite a few oil changes ago.   My oil analysis went back to normal tolerances after that as well.

My advice would be to not let the maintenance get too invasive unless there are signs that it needs to be.   Personally, I never even pulled a cylinder.   We did borescope mine and do compression tests and didn't see anything too concerning, and I'm very glad we didn't bother taking anything apart that didn't need to be.

 

[Guest]

If there was enough metal circulating in the oil system to destroy your prop governor, I wonder how the crankshaft journals look?

Clarence

[bradp]

1 hour ago, jetdriven said:

I wouldn’t put anything other than DLC or roller lifters in an engine these days. But that certainly looks like  lifter fragments. 
It could be Cascades to embed it metal in the bearings, score crank, trash oil pump, scored cylinders. That metal does a number.
To top it all off, new cylinders are 6 to 9 months out lead time. And if you call triad for example, and say hey I want to send my engine to you for an overhaul you’re not going to get it for nine months.

9 months… Like a new baby, Byron 

[PT20J]

33 minutes ago, M20Doc said:

If there was enough metal circulating in the oil system to destroy your prop governor, I wonder how the crankshaft journals look?

Clarence

Interesting question. I’ve heard Mike Busch claim that the filter will keep any metal from getting to the journals. Sounds right. BUT…my #4 cylinder broke an oil control ring, took out a chunk of the piston skirt and we found metal in the filter and part of the ring in the suction screen. Pulled the #4 con rod and found metal embedded in the big end bearing. The crankshaft looked OK though, so the bearing did it’s job (bearing material is a lot softer than the hardened crank pin). But, that is the extent of my experience. I’d be in what other maintainers have actually experienced.

Skip

[EricJ]

1 hour ago, M20Doc said:

If there was enough metal circulating in the oil system to destroy your prop governor, I wonder how the crankshaft journals look?

Clarence

I don't think the metal killed the prop governor, I think the prop governor was the source of the metal.   It is the model of governor that had the AD for the failing bearing, but I don't know whether that had anything to do with it or not.   I think it started failing and just ate itself.    We took the prop off and I took it to the same prop shop that did the governor and it was clean, so I don't think the metal went anywhere significant other than the filter.   If it was damaging the bearings I'd suspect that would show up in the oil analysis, but it's not showing anything.

[A64Pilot]

I think pulling the cylinder will tell the tale. 

So far as all of the metal being caught in the filter, no that’s not happening, but hopefully most of the metal big enough to cause damage is. Some get lucky, some don’t, but until you inspect you won’t know. But I’d bet lunch that steel is imbedded in the bearings 

The Lycoming SB requires all bearings and several other items to be replaced, but they aren’t high $$$ parts and really should be replaced and putting in new bearings in a mid time engine will add maybe 1,000 hours to the life of the bottom end, it’s one way many engines can go so far past TBO, because the wear items were replaced at mid time, as far as the crank is concerned you just reset the clock, and top overhauls are easy.

Part of the discussion that ends up costing money is do you send the crank off to be magnafluxed and polished if it mikes out OK, and do the cases go out to be dye penetrate inspected for cracks and repaired if any are found, how about the rods being reworked?

Edited September 30, 2021 by A64Pilot

[mike_elliott]

You can probably find the rest of the tappet and cam lobe in the suction screen, Brad. (well, almost all the rest). Consider getting the DHC tappets and there is an STC for a drilled cam (centrilube) worth considering. Notice I am placing my bet on the cam lobe and tappet being the source. Stuck Ex. valves usually cause such an event, but you can find tons of stuff blaming it on climate change in FL, like everything else.

[Amelia]

Think I told the story a few months ago. Oil filter was all sparkly. Much metal,  both ferrous and nonferrous. My A&P looked glum, spoke of engine overhaul and months of down time, not to mention the price of a small house. Told him I wanted a second opinion. He rubbed his chin. Pulled a stool up to the bared engine, pulled some pieces out, and offered me another opinion. “Your lifters are crap.” That lopped a zero off the bill. It still took weeks,  but that was a parts supplier’s incompetence. Much easier than rebuilding the engine.

[bradp]

1 hour ago, Amelia said:

Think I told the story a few months ago. Oil filter was all sparkly. Much metal,  both ferrous and nonferrous. My A&P looked glum, spoke of engine overhaul and months of down time, not to mention the price of a small house. Told him I wanted a second opinion. He rubbed his chin. Pulled a stool up to the bared engine, pulled some pieces out, and offered me another opinion. “Your lifters are crap.” That lopped a zero off the bill. It still took weeks,  but that was a parts supplier’s incompetence. Much easier than rebuilding the engine.

You’re a lucky continental owner @Amelia, no way to replace lifters without splitting a case for these 4-cyl lycomings. 
 

I’ll blame it on living a few miles from the Atlantic ocean for now, and one other time in the planes history.   Only thing that comes from the Atlantic is cyclones and spalling. :-)

[lotsofgadgets]

4 hours ago, EricJ said:

Proceed carefully, or you may wind up spending money unnecessarily.

My IO-360-A3B6D started making a significant amount of metal a few years ago.   Since it was under the max amount specified in Lycoming's guidelines (which is a huge amount), I let it go for a bit.   The shop that had done the last rebuild and Lycoming both had reps at the local IA seminar, and when I talked to each of them separately about it they both said to just keep running it as usual and monitor it.   It kept making a lot of metal for a few oil changes, and then started tapering off.   It was running fine, made good compression and power, so I wasn't too worried about it and figured whatever was wearing was clearancing itself or something.

Then my prop governor started acting up, got really slow on runup, and then on the next flight's runup got much slower.   That was unusual, so I aborted the flight and we figured out that my prop governor was toast.    I took it to the local prop shop and they said essentially all of the internals were worn so badly that it would cost as much to rebuild it as to buy a new one, so I bought a new one.

I've seen very little metal in the oil since then, and that was quite a few oil changes ago.   My oil analysis went back to normal tolerances after that as well.

My advice would be to not let the maintenance get too invasive unless there are signs that it needs to be.   Personally, I never even pulled a cylinder.   We did borescope mine and do compression tests and didn't see anything too concerning, and I'm very glad we didn't bother taking anything apart that didn't need to be.

 

Your experience parallels mine almost exactly.  Initially some metal was noticed during annual.  My IA told me to keep an eye on it and continue flying unless it gets worse.  Compressions were in the high 70's, seemed to have plenty of power, etc.  What caused me to pull the cylinder was an occasional vibration and drop in EGT on the #4 cylinder.  Multiple mechanics explained away the problem as fouled plugs, cleaned them and sent me on my way.  After 4 incidents of this in a little over a year I was convinced there was more going on.  A different A&P pulled the exhaust to get a look at the valve and noticed coking on the stem.  This is why we wound up pulling the cylinder.  At that point it was game over for the engine.  The damage to the cam lobes was obvious.  Two of the cam lobes are almost round instead of egg shaped, several of the lifter faces are concave instead of flat.  Like you, my prop governor was damaged beyond economical repair and I had to purchase an replacement.   To be safe I bought all new hoses and sent the oil cooler and prop out for overhaul.  I don't want any chance of old metal contaminating the new engine.

 

[bradp]

Courtesy of Lynn and Nathan - front shared intake lobe spalled and intake lifters are the source of the metal.  Typical lycoming-oma.  I’ll blame COVID I guess.  
 

Im starting to make some calls.  One major engine shop uses superior lifters.  Another (NC)uses lycoming factory parts only.   Nobody knows about the DLC coated lifters when I asked.   Is this what lycoming is sending out as new parts these days? 
 

-b

[ArtVandelay]

I thought DLC coating was the only option when using factory parts?
I used Zephyr and I have same engine FWIW.

[EricJ]

Glad you found it.  Sorry you found that.   

 

[carusoam]

Bummer…

Thanks for sharing the pics…

@Freemasm might want to have a look at the pics…

Best regards,

-a-

[Yetti]

2005 is consistent with the bad metallurgy time frame.   More to the end, would be interesting to know when the cam was made.

[bradp]

Is the mfr date stamped on the CAM?

 

It will make a nice desk lamp, I'm thinking. 

[David Lloyd]

Brad, have a friend that used to have a flight school and had a dozen or so engines overhauled by Triad.  He also had two for his personal Seneca and one for his Bonanza done there. The 160 horsepower motors generally went 3000 hours before overhaul, although I did see one fail due to a cracked case and one with missing cam lobes at 2500 hours.  I had them do an invasive prop strike inspection on the IO360 in my RV.  Most likely use them again when the time comes. Their sister company, H&H Propeller got our prop and governor repairs and overhauls as well.  On time within reason, price in line with other shops, plus they are nearby.

[bradp]

Figured I’d follow up.  Got the plane back a couple of weeks ago.  Total downtime was about 6 Months to the day mostly  because the engine and prop went in sequence instead of all at once (that one was on me deciding last minute not to send to the local prop shop and instead get it down to @Cody Stallings who did an awesome job on it).   The work done included:

* engine Iran with new oil pump, cam and followers, cylinder OHs and consumables.  So far I’m very happy with the work done at Midwest Aircraft Services (I believe @scottfromiowa gave me the recommendation along with a couple of guys on beech talk).  They had all lycoming OEM parts including cam and DLC lifters.  

* Prop done by Cody 

* New governor via Truespeed aero governors. Can’t recommend Adil highly enough.  He knows his stuff.  We determined that for my unairworthy but working Frankenstein-governor collection of parts, it was cheaper to use it as a core and get a new governor.  

* Lynn finished up the annual and rebuilt the nose gear, replaced a bunch of hoses,  flushed out the oil cooler and inspected and repainted the engine mount frame, replaced new lord mounts .
 

Anyway, she’s running well, temps have been dropping and oil consumption has been normalizing.  
 

It’s good to be flying again.  

[A64Pilot]

If it’s not to personal, how bad was the parts bill for the engine?

[201Steve]

2 hours ago, bradp said:

Figured I’d follow up.  Got the plane back a couple of weeks ago.  Total downtime was about 6 Months to the day mostly  

Good for you, Brad. The good news is, it was only down for six months one time.

I elected to have the beloved Jewell do my engine  and within 60 hours it started eating the cam. That was after they screwed up everything else they attempted to work on. So it went down for another 6 months. Now that Ive given them plenty of time to do something by way of the right thing, and they’ve chosen to do nothing, I’ll be posting the full PIREP soon. BUT I just got it back from Zephyr and Cole and am ecstatic with the work, and to be flying again. 

Congrats!