Low oil pressure....again

[powder_hounder]

I was on my way back from MN this past weekend and oil pressure dipped to 50 psi 1.45hrs into the flight. I departed with 6.25 qts and landed with 3.75 with lots of oil on the belly behind the breather tube.  I stopped short of home and left it at a reputable shop at KARR. Their service manager emailed me yesterday morning with not-so good news.  

Note:  I replaced cylinder #4 1.5 years ago and the engine has approx 1450 hrs on it.  Opinions, comments, and suggestions for my next step (s) greatly appreciated!

Brian,

We finally had a chance to look at your engine first thing this morning.  This is what we see.

Engine only had 3 quarts of oil in it by the dip stick before starting anything.  This would start causing a low oil pressure condition with the oil being that low.
 

No external oil leaks to speak of .

Borescope inspection found cylinder walls pitted from corrosion, scoring in several cylinders, #3 has some nice ones, cylinders have no honing marks remaining and are polished where not corroded.  Large amounts of carbon on the pistons from oil burning. Large amounts of oil puddle in the cylinders.

Ran the engine to temp after adding 1 quart for the run.  Runs not bad, temps look good, sounds good.

Compression check hot #1-57, #2-78, #3-77 and #4-73 all over 80.  Compression is a misleading due to the amount of oil in the cylinders is sealing the pistons to cylinder walls.

We did a pull thru test turning the engine slowly and two cylinders do not hold compression at all, almost no compression.

Cut open the oil filter and once again not too bad, but some aluminum and ferrous particles, lots of carbon. 

My concern would be the scoring.  What has been in these cylinders.  
 

Looks like you have at least three cylinders, but #4 which has been off doesn’t look any better have lost total oil control.  Corrosion pitting will cause this along with it accelerates ware on the rings.  

I would recommend removing two cylinders, look inside the engine and check the cam and lifters.  Review logs and if all looks good remove the other two cylinders and have all four reworked if possible.  They may need to be over  bored +.010 to .015 to remove the corrosion and get them back into correct bore shape.  

If inspection finds chipping or spawling of the lifters (which could be the cause of the scoring we see in the cylinder walls) would lead thing into a different direction since the only way to remove Lycoming T lifters is to split the crankcase.

Is it possible to get copies of the engine logs sent to me.  I believe you said it has about 1500 hours on it since overhaul. 

Thank you and let me know what you think and would like to do.

 

[flyboy0681]

As I learned from a somewhat similar experience not so long ago, Lycoming has a Service Bulletin out there where they highly recommend a tear down when oil pressure drops below 55psi, regardless of quantity remaining.

 

 

[Andy95W]

I think the only real questions are how much you trust the shop in KARR, how far away from home it is, how much cheaper would getting it potentially overhauled at your home airport, and whether or not you would trust it to get you the last few miles home.

On the surface, I think the service manager's write up was well reasoned and appropriate.

[kortopates]

How many years are on the engine?


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[75_M20F]

My engine is off and at Penn Yann for an overhaul right now. Mine needed a new cam and lifters so I opted for an overhaul considering all the labor involved.

[MooneyBob]

My engine got shipped today to Aero Engines of Winchester today.

I had elevated metals in the oil according to the Blackstone lab, I found some metal flakes in the filter. I have removed two cylinders yesterday and found that lifters are like a surface of the moon. I could see some scars of the cam lobes too. After I have removed the engine found metal in the governor screen and oil suction screen. Nothing crazy but it was there. So the governor and prop needs to be check ( both overhauls last annual). 

Engine is 973hrs since new in 1999 but previous owner put little hours for last 15 years. I have flown 500hrs last 3 years when it finally gave up.  

I will wait for the report from the shop and we will decide next steps. 

[powder_hounder]

1 hour ago, Andy95W said:

I think the only real questions are how much you trust the shop in KARR, how far away from home it is, how much cheaper would getting it potentially overhauled at your home airport, and whether or not you would trust it to get you the last few miles home.

On the surface, I think the service manager's write up was well reasoned and appropriate.

 

Hi Andy,

It's a reputable shop and I wouldn't have a problem with having them do the work other than possibly being on the expensive side.  My home airport, C56 (Bult Field) is 15 mins to the SE by Mooney and I would have no problem filing up the oil with 8 qts and flying it elsewhere.  The reason I stopped at KARR is my home airport doesn't have services other than a few guys doing annuals in your hangar.  KARR has a few good shops on-field, and I spoke with one of the other shops already and he's bidding on the overhaul.  If I brought is anywhere off-field, I'd take it 15 mins to the north to Poplar Grove Airmotive which is very reputable and $70/hr shop rate.

[powder_hounder]

2 hours ago, flyboy0681 said:

As I learned from a somewhat similar experience not so long ago, Lycoming has a Service Bulletin out there where they highly recommend a tear down when oil pressure drops below 55psi, regardless of quantity remaining.

 

 

I'l have to look that up.  Do you happen to know the SB number offhand?

[powder_hounder]

1 hour ago, kortopates said:

How many years are on the engine?


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1450 hours and she was overhauled last in 1999.

[powder_hounder]

1 hour ago, Mooney_Mike said:

My engine is off and at Penn Yann for an overhaul right now. Mine needed a new cam and lifters so I opted for an overhaul considering all the labor involved.

Hi Mike,

I'd be interested in learning more about Penn Yann overhaul costs.  They would certainly be a good option for me.

[flyboy0681]

Just now, powder_hounder said:

I'l have to look that up.  Do you happen to know the SB number offhand?

It was sent to me by a friend via email but I'm wasn't able to quickly find it. I'll attempt again tomorrow.

[kortopates]

Just now, powder_hounder said:

1450 hours and she was overhauled last in 1999.

That's surprising with an average of about 80hr a year.  Hopefully the cam is fine and you don't need to overhaul, but if you did, you might be interested in cerminil/nickel cylinders to keep the corrosion out of the cylinders - but I don't think they are available on the Lyc angle valve cylinders, at least not from Superior.  

[powder_hounder]

44 minutes ago, MooneyBob said:

My engine got shipped today to Aero Engines of Winchester today.

I had elevated metals in the oil according to the Blackstone lab, I found some metal flakes in the filter. I have removed two cylinders yesterday and found that lifters are like a surface of the moon. I could see some scars of the cam lobes too. After I have removed the engine found metal in the governor screen and oil suction screen. Nothing crazy but it was there. So the governor and prop needs to be check ( both overhauls last annual). 

Engine is 973hrs since new in 1999 but previous owner put little hours for last 15 years. I have flown 500hrs last 3 years when it finally gave up.  

I will wait for the report from the shop and we will decide next steps. 

Hi Bob,

That's a shame, so little time on your engine and already need to overhaul.  I guess that's what happens when they sit.  I would be curious to learn more about their overhaul costs.

I need to determine if I want the shop at KARR to pull two cylinders so they can check the cam and tappets for condition.  

[powder_hounder]

16 minutes ago, kortopates said:

That's surprising with an average of about 80hr a year.  Hopefully the cam is fine and you don't need to overhaul, but if you did, you might be interested in cerminil/nickel cylinders to keep the corrosion out of the cylinders - but I don't think they are available on the Lyc angle valve cylinders, at least not from Superior.  

I saw a Lycoming ad in the latest Trade-A-Plane about those nickel cyls.  Was going to look further into it.  The weird thing is the plane has been located in Chicago since it was born and the current engine hasn't been permanently based further than 60 miles from Chicago since it was last overhauled. I and the previous owner fly regularly.  I am beginning to wonder if it's partly operator error.  I change the oil 25-50 hrs and I run 50F rich of peak of hottest cyl.

[MooneyBob]

29 minutes ago, powder_hounder said:

Hi Bob,

That's a shame, so little time on your engine and already need to overhaul.  I guess that's what happens when they sit.  I would be curious to learn more about their overhaul costs.

I need to determine if I want the shop at KARR to pull two cylinders so they can check the cam and tappets for condition.  

I don't know the cost yet as we will discuss the options after they tear it down. I will post it as soon as I know. 

[powder_hounder]

Just now, MooneyBob said:

I don't know the cost yet as we will discuss the options after they tear it down. I will post it as soon as I know. 

That would be really helpful.   Thanks Bob.

 

[powder_hounder]

49 minutes ago, powder_hounder said:

 

Hi Andy,

It's a reputable shop and I wouldn't have a problem with having them do the work other than possibly being on the expensive side.  My home airport, C56 (Bult Field) is 15 mins to the SE by Mooney and I would have no problem filing up the oil with 8 qts and flying it elsewhere.  The reason I stopped at KARR is my home airport doesn't have services other than a few guys doing annuals in your hangar.  KARR has a few good shops on-field, and I spoke with one of the other shops already and he's bidding on the overhaul.  If I brought is anywhere off-field, I'd take it 15 mins to the north to Poplar Grove Airmotive which is very reputable and $70/hr shop rate.

I'll need to get the shop rate for the place where my plane is located right now.  I'm guessing if I tell them to pull two cyls to check the cam and lifters and they don't like what they see, they won't put everything back together and then I'm stuck with them.

[Andy95W]

Good luck, please keep us posted.  

[75_M20F]

1 hour ago, MooneyBob said:

My engine got shipped today to Aero Engines of Winchester today.

I had elevated metals in the oil according to the Blackstone lab, I found some metal flakes in the filter. I have removed two cylinders yesterday and found that lifters are like a surface of the moon. I could see some scars of the cam lobes too. After I have removed the engine found metal in the governor screen and oil suction screen. Nothing crazy but it was there. So the governor and prop needs to be check ( both overhauls last annual). 

Engine is 973hrs since new in 1999 but previous owner put little hours for last 15 years. I have flown 500hrs last 3 years when it finally gave up.  

I will wait for the report from the shop and we will decide next steps. 

My gov was contaminated with metal and could not be overhauled. $1750 for  one of those.

[75_M20F]

1 hour ago, powder_hounder said:

Hi Mike,

I'd be interested in learning more about Penn Yann overhaul costs.  They would certainly be a good option for me.

The Penn Yan Aero overhaul process is the result of over 70 years of experience overhauling thousands of Lycoming and thousands of Continental engines installed in all kinds of airframes flying in all kinds of environments around the world.

The Penn Yan Aero proprietary overhaul process is FAA Approved and incorporates dozens of unique techniques that result in a smoother-running, longer-lasting engine that helps make flying safer and lowers operational costs. Fleet Operators and FBOs repeatedly specify Penn Yan Aero overhauls because they provide reliable economy.

Penn Yan Aero Overhauled IO-360-A1A Includes

 

• Friendly, Highly Experienced and Knowledgable Staff Devoted to Helping You Find the Best Answers to Your Engine Needs
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• Penn Yan Aero’s Highly Developed, FAA Approved, Proprietary Overhaul Process that Results in Reliable, Smooth-Running, Long-Lasting Performance
• Overhauled to Lycoming’s New Engine Fits and Tolerances, as a Minimum
• Weight-Matched Set of New Lycoming Pistons, Rings, Wrist Pins
• Cylinder Options as available
• All Parts, New and Overhauled, are Critically Inspected and Evaluated; Benchmarked to Lycoming’s New Engine Fits and Tolerances to Ensure Penn Yan Aero’s Stringent Quality Standards
• Crankshaft and Rotating Assembly Dynamically Spin-Balanced to within 0.20 Ounce/Inch Grams of Lycoming’s New Engine Specifications
• New Camshaft and Lifters
• New Bearings and Bushings
• New Oil Hoses, Seals, Bushings, and Gaskets
• New Slick Ignition Harness
• New Champion Spark Plugs
• New SkyTec Lite Weight Starter
• Certified Bendix Magnetos
• New Champion Oil Filter
• Certified Fuel Injection System
• New or Certified Fuel Pump
• New Miscellaneous Nuts, Washers, Bushings, and Springs, as Needed and Required
• Current and Compliant with all FAA Airworthiness Directives and Manufacturer’s Service Bulletins and Letters
• Set-Up and Tested Via Penn Yan Aero’s Rigorous 100 Minute Proof-Positive Test-Run and Post-Run Inspection
• Penn Yan Aero’s Warranty: 100% Parts and Labor for 3-Years or to Lycoming's Maximum Recommended Time Between Overhaul (TBO), Whichever Occurs First, Supported Worldwide and Transferable from One Owner to the Next
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Penn Yan Aero Overhauled IO-360-A1A
with Penn Yan Aero Overhauled Steel Cylinders
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with New Factory Cylinders
$28,918 / $259 per month

 

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Edited February 24, 2017 by Mooney_Mike

[kortopates]

56 minutes ago, powder_hounder said:

I'll need to get the shop rate for the place where my plane is located right now.  I'm guessing if I tell them to pull two cyls to check the cam and lifters and they don't like what they see, they won't put everything back together and then I'm stuck with them.

Exactly, once you start disassembling its highly unlikley it will go back together until its been repaired. So best to choose wisely now.  Where you are at may be fine, but best to make that choice now rather than have no choice after its opened up. 

[carusoam]

Powder,

1) Get a photo like the ones Mike is showing.

2) it probably requires removing two cylinders to see all the spots.   Challenge is, there are limitations of how many cylinders can be removed at one time...

3) start with one cylinder to get a feeling.  Missing lobe parts and surface of the moon lifters is typical of a cam gone too long without flying.

4) get pictures of the cylinder walls. Everyone has a dental camera nowadays....  once all the cross hatchings are missing from the surface, it is probably time to rehone/OH the cylinder.

5) question to ask... why did the oil dissapear this flight? The cylinders have been aging slowly for a while...  suspect that an oil ring has finally broken.

6) all those quarts of oil probably passed in the cylinder with the broken oil ring.

7) If you want to guess on a cylinder to work on...  find the one that is missing the oil ring.  Pull the four bottom spark plugs.  One of them is going to look very oily compared to the others.

8) did you see a whole bunch of oil coming out of the exhaust pipe? Quarts of oil have left the engine, probably through the exhaust pipe...

9) if you successfully find a single bad cylinder with a broken oil ring. Get it OH'd with new rings.

10) if you find out that lobes are missing and lifters look like the surface of the moon.  Start planning the engine OH.

11) perform an oil change, look very closely for metal bits in the filter and screens, indicating the cam has already come apart.

 

Private Pilot ideas.  Not a mechanic. These are the things that pilots look for and share on MS.

 

Best regards,

-a-

 

Edited February 24, 2017 by carusoam

[kortopates]

Bummer on all the metal - that's alot and no wonder your governor was shot.  

[MooneyBob]

8 hours ago, Mooney_Mike said:

This came out of my oil filter, YIKES! (Yes, all 3 of them)

I can't believe that oil analysis were normal? What lab did you use? Could you post a copy of the report by any chance?

Thanks. 

[75_M20F]

2 hours ago, MooneyBob said:

I can't believe that oil analysis were normal? What lab did you use? Could you post a copy of the report by any chance?

Thanks. 

Bob,

Yea, I know right? Well, it turns out that the metal off the cam and lifters was large enough to be caught in the filter. The particles never made it to the oil pan, so when a sample was taken it showed normal. (That was the explanation I was given)

I'm not going disclose which company I used / post the reports - (I see nothing positive to come out of pointing to a particular company in this thread)

 

 

 

Edited February 24, 2017 by Mooney_Mike