Top Overhaul of Not?

[jlunseth]

Take it in immediatly, have them change the oil and when they do, make them remove the quick drain and let the oil drain out of the full sized hole.  That allows most or all of the "swimmers" to depart.  Than have them get a seal kit for the quick drain, clean the drain, and install the kit.  When the oil was drained in Canada after the emergency descent and landing the mechanics thought I had blown all the oil out.  No.  We found a quarter-sized piece of rubber likely shorn off when a new head was replaced, swimming around.  The mechanics surmised it had plugged the quick drain intake and prevented the last two and a half quarts from departing the aircraft.

If you see even a single drop on the nose tire you may have a problem about to happen.  I say "may" because there are other ways a drop can fall on the tire, but in my experience the most likely reason is the quick drain getting ready to fail

The leakage is pressurized, so there is misting as well as flow.  I had oil engrained in the fiberglass of the cowling everywhere, and migrating out for a couple of years.  We still see a little every now and then, and the incident was six years ago now.

I no longer accept anything under 1 qt. in 10 hours as "normal."  It is not in my engine.  

I now have the quick drain removed at every annual and at least checked for operation while the oil drains out the big hole.

Edited April 29, 2016 by jlunseth

[KSMooniac]

FWIW, I just replaced my quick drain.  I've been chasing a mysterious oil leak and thought it might be the culprit, so I changed it.  In reading the manufacturer's web site, they state they do have finite life and I re-used mine on my recent overhaul.  They're only ~$50 and easy to change, so I did it.  I still have a leak somewhere, though, and it is frustrating!  Most of the engine is dry, but something is leaking up front now I'm suspect the crank seal...

[Marauder]

1 hour ago, DXB said:

1 hour ago, DXB said:

Detecting leaks in the intake does seem like legit value added from oil analysis -  this is also the only concrete example that I've seen cited by Mike Busch as to how it helps.  

Funny story related to that - when I first was learing to do oil changes right after I bought my plane, I liberally slathered that Dow Corning silicon grease all over the filter gasket before installing. Don't do that.  The next oil analysis came back with sky high silicon and had me wigging out about an intake leak...until someone asked me how I install my filter.  

Detecting leaks in the intake does seem like legit value added from oil analysis -  this is also the only concrete example that I've seen cited by Mike Busch as to how it helps.  

Funny story related to that - when I first was learing to do oil changes right after I bought my plane, I liberally slathered that Dow Corning silicon grease all over the filter gasket before installing. Don't do that.  The next oil analysis came back with sky high silicon and had me wigging out about an intake leak...until someone asked me how I install my filter.  

Dev -- I think of the oil analysis like some of the medical tests that are out there. Like the prostrate PSA test. For years, everything above 4 was a trigger to do something. On my last physical my primary didn't even do one citing the growing evidence too many procedures were done based on the result.  Procedure that in the end were more risky than doing nothing.

But just like everything else in life, you need to decide whether any kind of pre-warning is valid. And for the record, I do them just to monitor the trend. Will it predict a catastrophic, probably not. Will it show you that you have too much fuel dilution, yep. Now what you do with the information is a different matter.

 

[Andy95W]

3 hours ago, Yooper Rocketman said:

I'm not a big fan of oil samples.  I do them occasionally now, but I don't expect they will warn me of anything I haven't already discovered from other signs already.

Tom

 

12 hours ago, DXB said:

But are those rapidly flattening cam lobe surprises killing anyone?  And aren't they apparent in the filter, if one chooses to look?  And without gross metal in the filter, would anyone ever pull a jug to find it? If not, what difference is oil analysis making here?

FWIW, I'm with Tom and Dev.  I've got nothing against oil analysis, but with the exception of Byron's silicon example, I'm not sure how effective it is compared to inspecting the filter and the suction screen at the bottom of the oil pan.

[DXB]

3 hours ago, Marauder said:

Dev -- I think of the oil analysis like some of the medical tests that are out there. Like the prostrate PSA test. For years, everything above 4 was a trigger to do something. On my last physical my primary didn't even do one citing the growing evidence too many procedures were done based on the result.  Procedure that in the end were more risky than doing nothing.

But just like everything else in life, you need to decide whether any kind of pre-warning is valid. And for the record, I do them just to monitor the trend. Will it predict a catastrophic, probably not. Will it show you that you have too much fuel dilution, yep. Now what you do with the information is a different matter.

 

Chris - The PSA test was developed by a famous urologist at my medical school while I was in training there. I'm amused you mention it because that is the exact analogy that got me thinking about all these oil analysis samples I'd been sending at $30 a pop when nothing else seemed to be wrong.  The analogy may be imperfect but there are parallels:

1. People really don't want to die early from either engine failure or cancer, so they are very interested in a test that might prevent either. 

2. Both patients and inexperienced aircraft owners like me don't really have enough perspective to judge the value of such tests, so we have to put some faith in expertise of others.  

3. The aforementioned urologist was a tireless advocate for using PSA as a screening test (i.e. a test to detect prostate cancer when there is no other reason to suspect it) in all men over 40 - kinda like sending oil analysis at every oil change routinely when nothing else seems worrisome. 

4. Primary care doctors for the most part wholeheartedly bought into it, making that urologist and others rich.  Developing a test that ALL men over 40 supposedly "need" is a goldmine - more than a smidge of conflict of interest here.  This may be a bit like mechanics buying into the value  of oil analysis at every oil change, to the benefit of companies that advocate and do the analysis.

Fast forward 20 years- routine PSA screening, once widely accepted, is rapidly falling out of favor.  In that time,countless men have suffered unnecessary worry and additional diagnostic procedures that were unproductive, and even unnecessary prostatectomies or radiation therapy.  But a very few men have actually been helped. Turns out the test sensitively picks up a whole lot of "cancers" that just don't matter- they will never do anything bad, and it can't distinguish them from the much more rare ones that are bad.  Is this a bit like oil analysis picking up every minor wear or corrosion-related blip in iron? Maybe - the potential for real harm from the oil analysis does seem less - but the worry is similar. 

So is all PSA testing worthless?  Absolutely not.  It is a powerful tool for following up men with prostate cancer for disease burden after treatment.  It also may be helpful to test certain high risk populations - but it remains controversial what these populations are - there are disparate published guidelines without consensus.  Will oil analysis prove similarly indispensable in narrower contexts - i.e. as a diagnostic test, not a screening test?  I dunno - it's not my field. 

[Marauder]

3 hours ago, Marauder said: Dev -- I think of the oil analysis like some of the medical tests that are out there. Like the prostrate PSA test. For years, everything above 4 was a trigger to do something. On my last physical my primary didn't even do one citing the growing evidence too many procedures were done based on the result.  Procedure that in the end were more risky than doing nothing.

But just like everything else in life, you need to decide whether any kind of pre-warning is valid. And for the record, I do them just to monitor the trend. Will it predict a catastrophic, probably not. Will it show you that you have too much fuel dilution, yep. Now what you do with the information is a different matter.

 

Chris - The PSA test was developed by a famous urologist at my medical school while I was in training there. I'm amused you mention it because that is the exact analogy that got me thinking about all these oil analysis samples I'd been sending at $30 a pop when nothing else seemed to be wrong.  The analogy may be imperfect but there are parallels:

1. People really don't want to die early from either engine failure or cancer, so they are very interested in a test that might prevent either. 

2. Both patients and inexperienced aircraft owners like me don't really have enough perspective to judge the value of such tests, so we have to put some faith in expertise of others.  

3. The aforementioned urologist was a tireless advocate for using PSA as a screening test (i.e. a test to detect prostate cancer when there is no other reason to suspect it) in all men over 40 - kinda like sending oil analysis at every oil change routinely when nothing else seems worrisome. 

4. Primary care doctors for the most part wholeheartedly bought into it, making that urologist and others rich.  Developing a test that ALL men over 40 supposedly "need" is a goldmine - more than a smidge of conflict of interest here.  This may be a bit like mechanics buying into the value  of oil analysis at every oil change, to the benefit of companies that advocate and do the analysis.

Fast forward 20 years- routine PSA screening, once widely accepted, is rapidly falling out of favor.  In that time,countless men have suffered unnecessary worry and additional diagnostic procedures that were unproductive, and even unnecessary prostatectomies or radiation therapy.  But a very few men have actually been helped. Turns out the test sensitively picks up a whole lot of "cancers" that just don't matter- they will never do anything bad, and it can't distinguish them from the much more rare ones that are bad.  Is this a bit like oil analysis picking up every minor wear or corrosion-related blip in iron? Maybe - the potential for real harm from the oil analysis does seem less - but the worry is similar. 

So is all PSA testing worthless?  Absolutely not.  It is a powerful tool for following up men with prostate cancer for disease burden after treatment.  It also may be helpful to test certain high risk populations - but it remains controversial what these populations are - there are disparate published guidelines without consensus.  Will oil analysis prove similarly indispensable in narrower contexts - i.e. as a diagnostic test, not a screening test?  I dunno - it's not my field. 

For those of us with scientific or engineering backgrounds, connecting the cause and effect of doing something like an oil analysis or using CamGuard is often hard to do without any significant statistical evidence it makes the difference -- yet people still do both.

[jlunseth]

7 hours ago, DXB said:

This is interesting.  My quick drain is the most oily thing under my cowl- I wipe off periodically but it always gets damp with oil, even above the tip.  But there's never any hint of oil on the cowl flap below or anywhere else in the cowl, so I figure no big deal.  But I wonder if it only leaks at high power when the case gets pressurized, and the stuff all blows out from the cowl flap opening and never touches anything else. Seems a little far fetched but your description above made me wonder.

I doubt it.  From my experience you get it all over the belly.  But that would be worth checking, if the leak is not too bad the belly just gets shiny and you might not notice it unless you are looking for it.  When the leak gets bad there is so much dripping off the belly you can't miss it, trust me on that.

It is always worth checking though, and you might just get a new seal kit installed at your next annual.

[Yooper Rocketman]

On 4/29/2016 at 9:00 AM, Godfather said:

Just curious if you ended up overhauling the engine or continued to push on?

Good Question.  I made a personal commitment when running over TBO I would monitor 5 things, and any of them that gave me a sign of engine issues it was time to put in a Reman.  1. Any major change in oil consumption.  2. Any major change in compressions.  3. Any major sign in the oil samples.  4. Anything found in the oil filter (or screen in the case of that F model IO360A1A).  5. Any other sign felt from the pilot seat that the engine may be developing a major issue.  

Back to your question; I installed a Reman and was amazed how much more power I had (after about 20-30 hours).  The old engine had certainly lost it's snort.

Tom