Metal in Filter, Oil Analysis, and New Trend *With final results

[201Steve]

I had to pull out the laptop for this one. I posted a couple weeks ago about some metal discovered in my IO-360-A1B6D. Motor has 400 hours since 2014 overhaul. Since then I've gotten my oil analysis back, boroscoped the cylinders, and discovered an interesting new development. It's quite possible the new development is separate from the metal findings, and honestly I didn't give it much attention at first. In the oil analysis, the analyst from Blackstone predicted that I potentially had wearing exhaust valve guide(s) or valve stem or both. After leaving the hangar today, I took a closer look at the oil/fuel droppings I normally leave behind after a run. I normally get some oil from the breather tube and I get a little fuel from the sniffle valve/induction sump. The fuel from the sniffle valve droppings looked like a larger than usual puddle. I stuck my finger in it and discovered that it was a mixture of fuel and oil. I started searching around for why the heck oil would be coming from the induction sump. After reading a few things here and there on the forums, it sounds like if you're getting oil into the intake sump, you could potentially be pulling oil through the intake valve guide. That's where I drew the connection. Blackstone says I could have failing valve guides, and oil in the sump means there is oil getting through the intake valve guide. Does that have anything to do with the metal in the oil filter? Maybe? It is ferrous metal that was discovered. I understand that valve guides are nickel (ferrous) and I'm not sure what valve stems are composed of. Currently, I am flying it to achieve 15 hours on new oil, so I can inspect filter again. On next oil change, I will also pull the screen to check for larger metal pieces. I did not get that far on the last one. This is the first time I've found any detectable metal in the filter. It had just come out of annual, I flew it from Georgia to California and back, and did the oil change when I got home. 38 hour interval.

It seems to be running fine. I've done a bunch of mag checks, run ups, power setting combo's, etc with no anomalies to speak of. Oil pressure normal, Oil temp normal, CHT's normal for my mixture settings (no problem keeping them below 380). EGT's, not really sure what to look for in this instance. Since I can't record data, I have no graphing to go off of. I am only producing 2660 max RPM but that's been consistent since I've owned the airplane for 200 hours 1.5 years.

Unfortunately, I have no engine data. I have an Insight G1 that measures CHT and EGT on each cylinder but it will not record data. I really hate that. I'm moving toward some upgrades, but at the moment, I'm trying to find my path for what may be the matter with the engine. I've been taking some video of the engine monitor with my phone, but I'm pretty sure it's useless unless I can put the information on a graph.

Today, I boroscoped all 4 cylinders, inspected the cylinder walls for scoring and valve faces for discoloration. Although I'm not an expert on boroscopy, everything appeared fairly normal. There was one cylinder whose walls looked a little smoother than the others, and I had a hard time getting a good image of the cross-hatching, so glazing I guess is a possibility, but that seems unlikely as from my understanding, glazing generally occurs during improper break-in. (NOTE: I also posted up some other pictures of some very odd looking 'scoring' that had no rhyme or reason to it, almost squiggly. I confirmed after running and rescoping that the odd markings came from scuffs from the boroscope rubbing against the bottom of the cylinder wall).

I've attached pictures of: Metal on magnet, a photo of each cylinders' valves, oil analysis, and oil/fuel puddle on hangar floor. Am I onto something here or is it likely unrelated? I didn't find anything worth uploading from inspecting cylinder walls.

Any and all feedback welcome....

[carusoam]

Logic is good, Steve!

pics that include the whole valve are better than partial valves...

If we are looking for a hot spot.... it might not be in the pic...   

Since we are looking for an intake valve failure.... (enough about the nice pizza looking exhaust valves...)

When valves get loose... oil has a tendency to drip down them... and turn crusty on the spark plugs....while it soaks them in oil...

In your case... seems a bit special.... oil is getting pressed up and out the other way... blending with the fuel.... at the intake end...

Sometimes these oddities occur after the engine is stopped... a few drops every now and again...  (how many quarts are missing?)

If a few quarts went missing... you may have a smoke show going on behind you... and oil drops falling out of the exhaust pipe...

The tiny metal bits seem consistent with the tiny motions that valves have... not like other metal makers that skive off long pieces...
 

Valve parts are typically made of one type of metal... they aren’t two pieces threaded together...

Since we are on the look out for probably one faulty valve... they don’t usually all wear out at the same time...
 

Was there anything about the intake valve pics that would make you asses one closer than the others?

#3 looks more clean than the others?
 

If you have a suspect valve... there is a ‘wobble test’ for worn guides...
 

Sounds like your logic is making good sense... 
check with your mechanic to see how to identify and fix the funky valve...

PP thoughts only, not a mechanic...

Best regards,

-a-

We can leave a note for @M20Doc...  (possible intake valve with worn guide...)

[201Steve]

Oil consumption seems to be up but only very slightly. I don't do a perfect job at measuring it, but it's within a normal range. 1 Qt every 7 hours or so. Trend hasn't changed much to speak of....

No oil in the exhaust pipe...

Need to pull bottom plugs at some point. Will probably do that at next oil change. Currently at 4.4 hours trying to get to 15 for a recheck... I will pull screen, pull bottom plugs, run a compression check, all in addition to the normal filter cut. As of now, I have no evidence to speak of to determine which cylinder (if any) are being problematic. It'd be a great time to have engine data....

Here are all the valve pics, or most of them. I wasn't sure how many pics it would let me upload. I have no idea if there is anything to look for on an intake valve. I just know to look for exotic colors and pizzas on the exhaust valves.

Thanks for the feedback @carusoam

[201Steve]

Also, if it makes any considerable difference, here are some videos of the metal jumping and a side angle for size perspective.

[Ragsf15e]

Can’t wait to see what you figure out!  I also have some oil that comes out the sniffle with my fuel drips.  I have replaced 3 cylinders and the last one is pretty tired so I assume it’s from that one but not sure.  I use more oil than you, maybe 1qt/4 but I think most of it is getting push past the rings.  
Your plane is newer than mine and some of the drains moved, but just confirm that you’re sure it’s the sniffle drain and not the mech fuel pump drain because oil can definitely come out there.  My drains are right next to each other, like attached.

[carusoam]

Upon review of the last set of valve pics...

There are a few light spots randomly dropped on a few of the surfaces on the exhaust valves...  Might be a dirty lens..? What would cause that?

Great video detail... the shape and size of the flecks are pretty good...
 

Best regards,

-a-

[Guest]

That much metal on a magnet doesn’t look good for your engine future, I’d suspect the cam and lifters.  The only way to know for sure is cylinder removal.  
Metal particles coming off the cam and lifters often become embedded in the soft aluminum piston skirts which then start to score the cylinder walls.

You can remove the valve rocker covers and inspect the valves and guides for wear by doing the rope trick to removed the springs.

Clarence

[201Steve]

19 hours ago, Ragsf15e said:

Can’t wait to see what you figure out!  I also have some oil that comes out the sniffle with my fuel drips.  I have replaced 3 cylinders and the last one is pretty tired so I assume it’s from that one but not sure.  I use more oil than you, maybe 1qt/4 but I think most of it is getting push past the rings.  
Your plane is newer than mine and some of the drains moved, but just confirm that you’re sure it’s the sniffle drain and not the mech fuel pump drain because oil can definitely come out there.  My drains are right next to each other, like attached.

It's possible its coming from somewhere else, but I can only chase so many leads at one time. lol. I've dealt with oil leaks before and I know it creep from one location to another, and being that hose is at the very bottom of the engine, it's possibly collecting and running down the side of the tube, rather than through it. We shall see....

[201Steve]

12 hours ago, M20Doc said:

That much metal on a magnet doesn’t look good for your engine future, I’d suspect the cam and lifters.  The only way to know for sure is cylinder removal.  
Metal particles coming off the cam and lifters often become embedded in the soft aluminum piston skirts which then start to score the cylinder walls.

You can remove the valve rocker covers and inspect the valves and guides for wear by doing the rope trick to removed the springs.

Clarence

can you get any reasonable analysis of the valve operation without pulling the spring? Reason I ask... I thought I'd recently read that the valve wobble test is done with the spring still on. Is that not true? Ah heck I'll just go look it up.

[Guest]

2 hours ago, 201Steve said:

can you get any reasonable analysis of the valve operation without pulling the spring? Reason I ask... I thought I'd recently read that the valve wobble test is done with the spring still on. Is that not true? Ah heck I'll just go look it up.

Lycoming SB 388C has options for both methods.

https://www.lycoming.com/sites/default/files/Procedure to Determine Exhaust Value and Guide Condition.pdf

Clarence

[201Steve]

7 minutes ago, M20Doc said:

Lycoming SB 388C has options for both methods.

https://www.lycoming.com/sites/default/files/Procedure to Determine Exhaust Value and Guide Condition.pdf

Clarence

Do you have preference to either? 

[Guest]

Just now, 201Steve said:

Do you have preference to either? 

If you suspect valve stem or guide wear/distress, I’d pull the keepers and springs for a more thorough examination.

Clarence

[201Steve]

Follow up on this thread. The gist of the conclusion is, I flew it enough times for 3 oil changes. The first discovery was ferrous metal at a normal 50 hour oil change. I flew it for 20 hours with the same amount relative to the hours flow, and then another check after 20 more hours. I'd boroscoped the cylinders twice with no abnormal findings. Up until 7 flight hours ago, I did not have data logging capability, but I do now. I was able to capture about 8 hours of flight previous to dropping it at the shop so I'll be curious to see if the pieces come together with that data as I learn more.  I also had a particle analysis done via Aviation Labratories who provided me the AMS# to classify the metallurgy. A follow up with that AMS number and Lycoming did not narrow anything down at all, they basically said "it could be 1 of 30 things" and thus essentially useless. "It's an airplant part" Very helpful, thanks.  Third filter discovery was the final straw and while still flyable, I took it to Jewell Aviation (Kennett MO) in anticipation of him discovering a spalled lifter/cam.  As suspected, all roads lead to corrosion for this IO360. See attached pictures of cam lobe. Engine will get pulled off and start the process of rehabilitation. I am happy to know that I did my homework and got it to an engine shop before I had to bother with crating it up etc. All signs led to cam, so rather than letting the field mechanic take it apart and ground the airplane, I used the data and got it to Jewell where it would be whispped away to the overhaul rack without delay. 

Picture number 3 is quite interesting. Here you'll find 2 random flat washers floating around in my rocker box. No, they don't go to anything inside of it, It'll just be the great mystery of how foreign parts ended up there. This may explain the elevated nickel in my oil analysis reports from Blackstone (as well as Chromium). Where I thought it may be a valve guide, it could easily have been nickel from a stainless steel washer. Per @PT20Js comments about the many diagnostic threads around here with no resolution later being reported, I thought it would be good information for the archives. Start to finish data.

Incidentally, I got a call from the customer service rep at Av Labs today to ask me how I liked my particle analysis report from 4 months ago. I told him it's funny he called today, because it got diagnosed in the shop today. Since he was looking for feedback, I told him it sure would be nice if you guys would link the data between AMS# reports and a follow up with the customer once the engine part is verified. That might actually give some value to the tool, if they would at least take a stab at the origin source themselves. The more data they have the better service they could provide, but in all, my experience with the service was lacking from the feedback standpoint. They take stabs at oil analysis all the time, why wouldn't they write a speculative narrative about particle samples as well?

 

[EricJ]

I think sometimes what happens with random small parts in the rocker covers, is that somebody had the cover off and used it as a parts tray until they were ready to reassemble, and whatever was left sticking in the oil in there just went back on with the cover.

My theory, anyway... 

 

[carusoam]

Nice details Steve!

Any chance you will see what the cam lobe follower surfaces will look like?

 

The cam lobe sure looks like a layer has gone away...  some sort of discoloration...

Best regards,

-a-

[201Steve]

@carusoam yes, I’ll have the full spread of pics soon enough. 

[201Steve]

More pics from the shop, holy cow. That is serious pitting. 

[MB65E]

Bummer!
I have not seen an oil sample with IRON above 65ppm when the camshaft was still good. 
-Matt

[201Steve]

4 minutes ago, MB65E said:

 

Bummer!
I have not seen an oil sample with IRON above 65ppm when the camshaft was still good. 

 

The last one, which was measured only 5 operation hours previous to the Teardown (28 on the oil) was 94ppm. This is all good feedback and hopefully helpful to someone when they are trying to diagnose similar problems/seeing similar trends. 

[carusoam]

Interesting that two followers look pretty good...

And two followers look like the moon...

Great pics!

Thanks for sharing them...

Cool... I can invite @Old Chub to the thread... he might find this interesting... 

Best regards,

-a-

[201Steve]

It is curious for sure. I found it interesting that, according to Dave Jewell, most of the compromised lifter faces are found on the front two cylinders, closest to the propellor. Mine were the the opposite, cylinders 3&4 closest to pilot. I probed him why that would be the case, why there is a trend in position of affected (or infected) positions and he had no good response. Simply that it was a trend. We also discussed the chicken/egg scenario. Are there scenarios that a cam lobe would deteriorate a lifter face, or is it always lifter face deteriorates cam. Unanswered questions. When I retire in 30 years I’ll get creative in controlled experiments and report back. But I may not care by then. 

[Ragsf15e]

28 minutes ago, 201Steve said:

It is curious for sure. I found it interesting that, according to Dave Jewell, most of the compromised lifter faces are found on the front two cylinders, closest to the propellor. Mine were the the opposite, cylinders 3&4 closest to pilot. I probed him why that would be the case, why there is a trend in position of affected (or infected) positions and he had no good response. Simply that it was a trend. We also discussed the chicken/egg scenario. Are there scenarios that a cam lobe would deteriorate a lifter face, or is it always lifter face deteriorates cam. Unanswered questions. When I retire in 30 years I’ll get creative in controlled experiments and report back. But I may not care by then. 

You gonna get DLC coated lifters on the reman?

[201Steve]

8 hours ago, Ragsf15e said:

You gonna get DLC coated lifters on the reman?

Yes. 

[EricJ]

13 hours ago, 201Steve said:

It is curious for sure. I found it interesting that, according to Dave Jewell, most of the compromised lifter faces are found on the front two cylinders, closest to the propellor. Mine were the the opposite, cylinders 3&4 closest to pilot. I probed him why that would be the case, why there is a trend in position of affected (or infected) positions and he had no good response. Simply that it was a trend. We also discussed the chicken/egg scenario. Are there scenarios that a cam lobe would deteriorate a lifter face, or is it always lifter face deteriorates cam. Unanswered questions. When I retire in 30 years I’ll get creative in controlled experiments and report back. But I may not care by then. 

In some older automotive engines there were wear patterns that were proportional to how far down the oil galley the components were.   In other words, the valves at the far end of the galley wore faster because they didn't get as much oil.   I think this meant that the oil galleys in those engines were insufficient, but the front cylinders are the last ones in the galley.   The basic lubrication diagram in the Lycoming overhaul manual doesn't show the order of distribution after the oil is split off to the lifters, but that may have something to do with it.   If the galleys get clogged up with dirt or sludge, the last guys in the pipeline will get less pressure. 

No idea whether that really has anything to do with it, but who knows.

 

[cnoe]

Welcome to the club 201Steve... and sorry for your troubles. See my lifter pic from 2017 below. Purchasing a Lycoming-powered plane is a crap-shoot at best since there's no effective way to inspect the cam/lifters (without cylinder removal).

I've now logged 674 hours on the new Lycoming cam and DLC lifters with no new metal. There are several of us on here who go to bed every night hoping that the DLC hype is for real. Time will tell.

In the meantime my engine lives on a closed-circuit dehydrator and enjoys 25-30 hour oil-changes (spiked with ~10 oz. of Camguard). And I can't remember the last time it went more than a week without flying.

CNoe