metal in the oil filter

[Jsavage3]

Shadrach,

No cylinder work on this bird yet.  I bought it 6 mos. ago knowing it was making metal because we found it in the oil filter during the pre-buy.  The seller adjusted the price accordingly, so I bought it hoping it was going to "clear up".  Now, after 35 hours and the 3rd filter cutting session, my fears have been confirmed.  Compressions?  That's the hard part -- the compressions, oil consumption, pressures/temps, oil analysis, everything has been great -- no sign of a problem...other than the continuation of fine, steel granules in the oil filter...and my A&P says it is a lot...not just a granule here-n-there.

I'm not willing to continue "trouble shooting" it because I find that I am driving myself crazy with worry everytime I'm sitting behind that spinning prop.  She runs great and makes good power, but I just cannot keep thinking about the "now I'm a glider" scenario and myself trying to explain to someone why I kept at it when I KNEW what the engine was doing.  Becoming a glider due to an engine failure that I did not anticipate, well, that's why we train for engine-out emergencies, right?  But, knowing what I know changes my comfort level.  Bottomline, the engine should not be making appreciable steel, i.e. more than the normal wear kind of sludge.  Lycoming's Service Instruction No. 1492D (item #8 a thru d) was quite helpful.

I've come to believe that it is likely the cam and that the likely outcome, were I to continue flying it, would be that the engine would gradually lose power as the cam lobes continued to wear.  It would not just stop making metal and it would likely not be a catastraphic engine failure; rather, the gradual loss of power.  Supposedly, the oil filter would keep any steel from getting to the bearings, so I shouldn't have to worry about that, but is the prop getting contaminated?  Or the prop governor? ... there are just far too many what-ifs going on here.  I fly the airplane for the transportation tool that it is -- night IMC over the mountains, etc -- and I have elected to correct the problem before continuing my travel pleasures.

I appreciate everyone's input and I will post what I find once we crack the case.

Blue skies!

[Kwixdraw]

You'll be better able to keep tabs on the engine after it's overhauled anyway. Once it's broken in and stabilized you can start the oil analysis to monitor whats happening and compare it to what you see in the screens and filter. Things will make more sense and you'll be able to feel confident in the engine.

[jelswick]

Squirrel's comment on a certain normal level and variance by aircraft as well as Kwixdraw's comment on starting oil analysis to monitor what's happening both line up with what I was told by Lycoming and A&Ps when I was selling used aircraft.   I honestly haven't done the consistent oil analysis on my aircraft, but for those who do, I've been told a normal amount of metal is expected and that the engines should deteriorate from freshly overhauled to when overhaul is needed again in a fairly consistent manner; that changes in that trend are cause for research and need to understand why the change to address potential issues.

If you don't regularly do oil analysis, then when it's noticed, you need to do a thorough analysis to understand it because you don't have the reference trend to compare it against.  I don't regularly, so not trying to sound preachy at all, but this might be reason I'll start.  I too think Jim you've made right decision on it.  And BTW, great to see another Mooney driver here in Columbus, Ohio!

[Shadrach]

Quote: Jsavage3

Shadrach,

No cylinder work on this bird yet.  I bought it 6 mos. ago knowing it was making metal because we found it in the oil filter during the pre-buy.  The seller adjusted the price accordingly, so I bought it hoping it was going to "clear up".  Now, after 35 hours and the 3rd filter cutting session, my fears have been confirmed.  Compressions?  That's the hard part -- the compressions, oil consumption, pressures/temps, oil analysis, everything has been great -- no sign of a problem...other than the continuation of fine, steel granules in the oil filter...and my A&P says it a lot...not just a granule here-n-there..............

[Jsavage3]

Ross,

Yes, it was ferrous metal -- steel -- the magnet collected nearly all of it.  The longer I took the magnet over the filter media, the more ferrous metal showed up.  There was the standard amount of non-ferrous sludge, but it was the sand-like pieces that loved the magnet that got my attention.

 

[KSMooniac]

You could send the filter contents in for analysis just like the oil sample... I would do that before splitting the case.

[jetdriven]

Here is what Lycoming says.   http://www.google.com/url?sa=t&source=web&cd=1&ved=0CBQQFjAA&url=http%3A%2F%2Fwww.lycoming.textron.com%2Fsupport%2Fpublications%2Fservice-bulletins%2Fpdfs%2FSB480E.pdf&rct=j&q=lycoming%20buletin%20metal%20oil%20filter&ei=uuqcTcfjEMPIcZCIme0F&usg=AFQjCNG7kT0Wwu4t_2qh8-IcPrQdVnb9Xw&cad=rja

 

Mike Busch:   http://www.avweb.com/news/savvyaviator/savvy_aviator_44_making_metal_195044-1.html

 

 

Personally Id follow the Lycoming service bulletin and not fly it IFR or night until it either clears or doesnt improve.  he former owner of Blackstone runs an oil filter analysis lab and can examine yourt filter.    It might be a piston pin plug which is actually not that big of a repair and can be fixed for a couple grand.   You could alsdo pull a cylinder and visually inspect the cam, we did this when doing the prebuy on our plane.

[tony]

I would save your money and forget the oil analysis.  I had great samples when I had bad followers.  You already know its steel. Just pull a rear jug and look at the four followers and the three lobes you can see.    I'll be willing to bet you'll find what you're looking for.  Also look for faint vertical lines on the piston below the oil ring.  If you have those they are created by the steel that’s floating around in the oil. With the right tools it’s a thirty minute task to take off and thirty minutes to reinstall.  But I bet you won’t be reinstalling

[Jsavage3]

I did an oil analysis when I changed the oil 25+ hrs ago -- the results came back in the green, i.e. normal.  My mechanic and I found that hard to believe considering how much metal we pulled out of the filter.  Do I want to do a tear-down, of course not, but I also know I won't put my family in the airplane knowing what I know right now.  As a result, the airplane is pretty useless to me until the issue is fixed.  My wife made me promise to take her to Oshkosh this summer, so I need to get busy!

I'm scheduled for the tear-down/repair in 2 weeks.  My plan will be to pull a jug or two and see where we're at.  I fully expect us to end up cracking the case.

If we do end up cracking the case, my plan is to have this engine repaired (not overhauled) which will be under half the cost of a field overhaul and less than a third of a factory reman.  Why not go the whole 9-yards?  First, this -A3B6D engine will be going into an experimental airplane (electronic ignition) in the next 3-5 years and 2nd, I want to wait on the overhaul until we figure out where we're going to go after 100LL goes away.  Once we know what is going to fuel our birds, I want to go back into the Mooney with an overhauled -A3B6 engine...I do not like single drive, dual mags.

[jetdriven]

Jim:

There is nothing wrong with splitting the case, swapping out the cam, lifters, bearings, rings, and taking a general look around in there, then reassemble.  People overfix things sometimes when they wont be putting another 2000 hours on it anyways.  Same thing they do with a prop strike, teardown, inspect, repair.  Id vote for the Ney nozzles or the FWF centrilube cam.  Its the Lycoming's only fault.

[tony]

I have just been down the road that Jim is about to take.  I would really take a hard look at the difference in price for the repair and the difference in price for a field overhaul.  The oil contamination probably scoured the housing of the oil pump you’ll want to take a hard look at that and you’ll want to get the crank checked as well.  A new cam, new lifters, sending the oil cooler out to be flushed, I would submit to you that there really isn’t much left to go all the way.  Along with dealing with the engine, you'll also need to overhaul the prop governor; those little pieces of metal can to damage the internal seals

I guess what I’m saying is the repair is only part of Jim’s issue; he’ll need to deal with the oil contamination as well.  I decided that a field overhaul was best.  I thought about the Ney nozzles for a while but to really make them effective, mitigating the corrosion, you would have to put in a per oiler.  The cost and the extra weight killed that idea.  I also thought about spending the extra money for the roller bearings but the engine shop talked me out of them.  Not enough historical data yet for me.  In the end the damage (corrosion) occurred was from lack of use.    I decided the best course was to use camguard and fly the thing regularly.

Jim whatever you decided will be the right answer for you.  I’m glad you’re dealing with the issue by taking a look inside and not ignoring it.  I did make one little change and that was to epoxy a small rare earth magnet to the second oil plug in the sump so I can easily check for metal at every oil change.  Good luck

 

[Shadrach]

 

Jim, I just went down the "split it and look around" road over the holiday.  I had a cracked crank case at 830hrs and decided to IRAN while the case was out for OH. We found surprisingly little wrong (other than the crack). Here is a list of what we did do:

1) New exhaust valve guides

2) Valves cleaned and relapped by hand

3) New main and rod bearings

4) New rod bolts

5) Reground lifters (each of ours had a sigle pit, smaller than a grain of salt. Would have gone to TBO, but...)

6) Crankcase Overhauled

Keep in mind, none of the above "needed to be done" but it was prudent to do all of the above while it was split.  At 220SMOH once the source of the metal is found, you will probably need little else attended to given that the filter media caught the metal. You're engine shop will explain the situation and recommend the best course of action. None the less, let us know what they find, especially if their reccomendation sounds over the top.

I used a local engine shop (sort of...about 50mls away) so that I could physically see what my machine looked like on the inside. I was amazed at how quickly they tore it down...maybe 3hrs until getting the case halves in a box.

The cost for the engine work was $3750 and I imagine the labor to remove/reinstall would have been almost as much had I not done it myself.  My IA charged $300 to periodically inspect, verify and sign off my work. I spent in the neighborhood of 50hrs on the R&R. I would expect you'll have around $7K-$10K in the repair depending on who does what.

I would not get too hyped on the Ney Nozzles, I've been told that they were designed predominately to address the cam/follower problems with the 320-H2AD engines.  I did consider them, but after seeing that my cam and lifters did not appear to be lacking lubricant at all during there first 830hrs, I decided it would be overkill. Never run a Lyc 4 banger below 900rpm for more than a second or two.  I think 1000-1100 is better...YMMV.

 

[Jsavage3]

All excellent points, Gentlemen.

My A&P/IA will be doing the work.  I've watched him overhaul engines before and I trust his methods.  He has quoted me $7500 to repair the engine only -- this will include many new parts.  The new oil cooler, overhaul of the prop governor and prop will bring me to somewhere around $10,000 out the door with a fresh annual.  It will still be a 1500-hour engine, but I trust that the safety factor will be greatly increased and I can actually relax knowing I've done the prudent thing regarding the safety of my family.  This plan won't help the resale value, but that's ok.

Bottomline, we won't make the final judgement until we remove a couple of jugs and look around...

 

[jetdriven]

Sounds like a good plan.   Are you sure you need a new (instead of flushed) oil cooler, and an prop and governor overhaul?  I thought you could have a repair station inspect and repair as necessary on those too.

 

You are grtting most of an overhaul that way on your engine and could fly it past 2000 hours "TSMOH", since it is almost completely overhauled anyways.

[Jsavage3]

I agree with your TSMOH comments for sure.  As long as she's running healthy, there's no reason why I cannot keep right on running her past the 2000-hour mark.

The prop is actually due for an overhaul, so that will get done either way.  The oil cooler could be flushed, but I've decided to just put a new one on in an effort to further isolate (get rid of) any & all metal contaminants.  The prop governor, well, we'll see.

[Jsavage3]

The engine is now in many little pieces.  As we expected, the cam shaft is bad -- 3 of the 6 cam lobes are rounded (both intake valve lobes and one of the exhaust valve lobes).  My A&P/IA tells me that based on what he sees, he figures the engine was only giving me 160 hp rather than the standard 200 hp.  He said I probably didn't notice it b/c (1) I'm fairly new to the airplane (35 hrs or so) and (2) the power-flow exhaust was adding some horses on the back end.  I thought I had a slick bird b/c I was seeing 157 KTAS at 24 squared and 9.2 gph.  He thinks she'll definitely pick up the pace for me...this is good.  No one buys a Mooney to fly it slow, right?

The crank looks good, but will need some polishing where the metal was getting "pressed through the bearings".  It, the case and a box of odds-n-ends are now at the engine shop for the cleaning/magna-flux magic.

The piston skirts are quite "abrased" from the metal particles and the cylinder walls will be getting bored to ten thousandths over as a result of corrosion/abrasion.

I've decided on the overhaul now that we're actually inside of it.  The original idea of a "simple repair" was, in actuality, going to end up basically being an overhaul anyway, I've since learned...

Bottomline, what I've learned so far is that if my engine is making metal, not only do I want to find out where it's coming from (and quickly), but also either get it fixed now or else deal with the damage that is caused by having metal go thru the bearings...cranks are expensive!

More to follow...

 

[tony]

Jim I'm sorry to hear about the condtion you found but welcome to the club.  My personal opinion is that you are going down the right road.  I think you'll be much happier in the long run. 

[Kwixdraw]

Don't forget your oil hoses. They need replacement every five years anyway so this might be the perfect time.