Io360 a1a cylinder blow by. Replace?

[Teddyhherrera]

21 minutes ago, MikeOH said:

That was my goal...and, I failed.  To be honest, though, I didn't really try that hard.  I wanted a relatively nearby shop with a good reputation.

Did you find one?

[Ragsf15e]

9 minutes ago, Teddyhherrera said:

Did you find one?

When my cylinder couldn’t be overhauled, I found an OH one at Western Skyways that they sent pretty quickly for a reasonable (in 2020) $1800.

[Shadrach]

14 hours ago, Teddyhherrera said:

Number 2 cylinder fouled a spark plug with a bit of oil. Compression 77, blowby evident at dipstick. Redid run up and spark plug is barely moist but with deposits after cleaning. AP thinks it's time for a new cylinder. All cylinders are nickel and the aircraft was IRAN in 2019, approximately 400 hours ago. 

 

Having just gone down the mile Busch YouTube rabbit hole, I'm thinking I should not change the cylinder. Am I correct?

What is the "evidence of blowby" at the dipstick?  From your post there seems to be no reason to pull the cylinder.  Oil on the plug could be minor leakage from one of the guides.  Is the plug actually oil fouled?...as in not firing due to oil saturation or is it simply wet upon inspection?  Certainly a borescope is warranted before anything more invasive. Seems trigger happy to be advocating for cylinder removal.

[M20F]

Unless I have missed it, don’t see what the consumption is. 

[Teddyhherrera]

2 hours ago, Shadrach said:

What is the "evidence of blowby" at the dipstick?  From your post there seems to be no reason to pull the cylinder.  Oil on the plug could be minor leakage from one of the guides.  Is the plug actually oil fouled?...as in not firing due to oil saturation or is it simply wet upon inspection?  Certainly a borescope is warranted before anything more invasive. Seems trigger happy to be advocating for cylinder removal.

I wonder the same. Borescoped today. Minor oil on cylinder wall, no crosshatch but streaks along. No hotspots to be seen anywhere BUT significant buildup. I've been running it super rich for like the last 300 hours which was my bad. 

[Teddyhherrera]

2 hours ago, M20F said:

Unless I have missed it, don’t see what the consumption is. 

In the summer, it's about 1 quart every 6-8 hours. Longer in the winter

[Shadrach]

10 minutes ago, Teddyhherrera said:

I wonder the same. Borescoped today. Minor oil on cylinder wall, no crosshatch but streaks along. No hotspots to be seen anywhere BUT significant buildup. I've been running it super rich for like the last 300 hours which was my bad. 

You said they were nickel cylinders?  No cross hatch on nickel.

[MikeOH]

3 hours ago, Teddyhherrera said:

Did you find one?

I'm using Lycon in Visalia, California.

[EricJ]

44 minutes ago, Teddyhherrera said:

I wonder the same. Borescoped today. Minor oil on cylinder wall, no crosshatch but streaks along. No hotspots to be seen anywhere BUT significant buildup. I've been running it super rich for like the last 300 hours which was my bad. 

It's normal for there to be a ton of deposits on the valves and head area and on top of the piston.   If the valves are reasonably symmetric (e.g., look like a pizza) that's okay.

Normal borescope pics with deposits below.

[DXB]

18 hours ago, Teddyhherrera said:

Number 2 cylinder fouled a spark plug with a bit of oil. Compression 77, blowby evident at dipstick. Redid run up and spark plug is barely moist but with deposits after cleaning. AP thinks it's time for a new cylinder. All cylinders are nickel and the aircraft was IRAN in 2019, approximately 400 hours ago. 

 

Having just gone down the mile Busch YouTube rabbit hole, I'm thinking I should not change the cylinder. Am I correct?

Hogwash on the A&P's rec if this is the only data they are considering in making the recommendation.  A dramatic and rapid rise in oil consumption would make it a consideration to identify the offending cylinder and pull it - it could be a broken ring or more often a stuck oil control ring, or a just a crosshatch that's been badly worn down.  Also note bottom plugs get oil on them pretty easily.  A oily top plug is much more problematic and usually comes with oil pooling in the cylinder and lots of oil consumption.  It can result a stuck oil control ring that MIGHT be freed with various solvent procedures including one Mike Busch advocates - but often this won't work, and you gotta pull it.  A borescope exam by someone who knows how to look for evidence of these things (possibly not your A&P) can guide decision making. 

[Teddyhherrera]

1 hour ago, Shadrach said:

You said they were nickel cylinders?  No cross hatch on nickel.

Well that's good news! Just streaks

[Teddyhherrera]

31 minutes ago, DXB said:

Hogwash on the A&P's rec if this is the only data they are considering in making the recommendation.  A dramatic and rapid rise in oil consumption would make it a consideration to identify the offending cylinder and pull it - it could be a broken ring or more often a stuck oil control ring, or a just a crosshatch that's been badly worn down.  Also note bottom plugs get oil on them pretty easily.  A oily top plug is much more problematic and usually comes with oil pooling in the cylinder and lots of oil consumption.  It can result a stuck oil control ring that MIGHT be freed with various solvent procedures including one Mike Busch advocates - but often this won't work, and you gotta pull it.  A borescope exam by someone who knows how to look for evidence of these things (possibly not your A&P) can guide decision making. 

His reasoning is that he doesn't want me stuck at a foreign airport with a fouled plug... I did get a second opinion with another person on the field that did borescope it today. He mentioned he had the same problem but with much higher oil consumption. He opted for the cylinder because he had one lying around but he was also of the school of "fly it and watch it."

[DXB]

12 minutes ago, Teddyhherrera said:

His reasoning is that he doesn't want me stuck at a foreign airport with a fouled plug... I did get a second opinion with another person on the field that did borescope it today. He mentioned he had the same problem but with much higher oil consumption. He opted for the cylinder because he had one lying around but he was also of the school of "fly it and watch it."

I wouldn't touch a cylinder just because of an oily bottom plug.  An oily top plug is a different story.  High but stable oil consumption within manufacturer limits (as a single data point) can also be watched. Having a spare cylinder available at the moment probably shouldn't influence decision making under most (all?) circumstances.

[hammdo]

Extra plug or put a fine wire plug in the lower cylinder spark plug location. 
 

id try that after ring flush…

-Don

[EricJ]

3 hours ago, Teddyhherrera said:

His reasoning is that he doesn't want me stuck at a foreign airport with a fouled plug.

Do you have basic mechanical skills?   As an owner/operator changing or cleaning plugs is something that you are allowed to do.   If you're comfortable opening up the cowl and changing a plug, there's no reason to worry about being stuck anywhere for that reason.  Many people (myself included) carry an extra plug or two and enough basic tools to do these kinds of things.

Even without that, many airports have on-site mechanics that deal with transient airplane breakdowns all the time.

 

[Teddyhherrera]

21 minutes ago, EricJ said:

Do you have basic mechanical skills?   As an owner/operator changing or cleaning plugs is something that you are allowed to do.   If you're comfortable opening up the cowl and changing a plug, there's no reason to worry about being stuck anywhere for that reason.  Many people (myself included) carry an extra plug or two and enough basic tools to do these kinds of things.

Even without that, many airports have on-site mechanics that deal with transient airplane breakdowns all the time.

 

I watched him. And he said I could do it but that I shouldn't because it's not in my scope of practice as an owner 

[EricJ]

1 hour ago, Teddyhherrera said:

I watched him. And he said I could do it but that I shouldn't because it's not in my scope of practice as an owner 

It absolutely is within your legal scope as an owner.   The official FAA term is "Preventive Maintenance", which can be done by any owner or operator.   A non-comprehensive list of "Preventive Maintenance" tasks is listed in Appendix A of Part 43 of the FARs.   See Part (c) of Appendix A:

https://www.ecfr.gov/current/title-14/chapter-I/subchapter-C/part-43/appendix-Appendix A to Part 43

Part (c) 20. Replacing or cleaning spark plugs and setting of spark plug gap clearance.

So it is specifically listed as allowed, along with things like changing tires, changing oil, etc.

There is also a legal opinon letter from the FAA that says that the list in Appendix A is not comprehensive, so may not be limited to what is listed.
So if you are handy with a wrench and it is something that you are apt and capable of doing safely and willing to do, it is within your legal scope to do as an owner or operator.   If you do elect to do such things, you are also required to log the maintenance as described in Part 43.9.

[Teddyhherrera]

2 minutes ago, EricJ said:

It absolutely is within your legal scope as an owner.   The official FAA term is "Preventive Maintenance", which can be done by any owner or operator.   A non-comprehensive list of "Preventive Maintenance" tasks is listed in Appendix A of Part 43 of the FARs.   See Part (c) of Appendix A:

https://www.ecfr.gov/current/title-14/chapter-I/subchapter-C/part-43/appendix-Appendix A to Part 43

Part (c) 20. Replacing or cleaning spark plugs and setting of spark plug gap clearance.

So it is specifically listed as allowed, along with things like changing tires, changing oil, etc.

There is also a legal opinon letter from the FAA that says that the list in Appendix A is not comprehensive, so may not be limited to what is listed.
So if you are handy with a wrench and it is something that you are apt and capable of doing safely and willing to do, it is within your legal scope to do as an owner or operator.   If you do elect to do such things, you are also required to log the maintenance as described in Part 43.9.

I've been apprehensive in doing my own maintenance but this ordeal has made me realize the need to actively participate and conduct my own maintenance and inspection. I trust my AP but I suppose many of these things aren't as black and white as I thought 

[Ragsf15e]

16 hours ago, Teddyhherrera said:

I've been apprehensive in doing my own maintenance but this ordeal has made me realize the need to actively participate and conduct my own maintenance and inspection. I trust my AP but I suppose many of these things aren't as black and white as I thought 

You’ll save money and more importantly you’ll know so much more about your airplane!  As you get better, you’ll be able to show up to your A&P having done the troubleshooting and already knowing what needs fixed/replaced.  It really works so much better.  You’ll quickly get a good idea of what you’re legal and capable (they can be different) to fix vs what you need A&P help for.

[Teddyhherrera]

Flew her this morning and really leaned her out over about an hour. Take off power was definitely there and everything seemed better than it had ever been. I was running way too rich. I still have a blowby problem but nowhere near as bad as I had thought. I pulled the lug and it was barely wet. In my inspection, I also noticed the dipstick housing was a bit loose and leaking a small amount from the base. Fixed also. I will continue to monitor the situation.

[PT20J]

The dipstick tube on Lycomings gets loose. Tighten it using the hex section molded into the tube, but carefully -- it's plastic. Then get the safety wire really tight. Afterwards, just don't honk down on the dipstick. Many people over tighten them. There is a o-ring at the top and it only takes light pressure to prevent a leak as there very little pressure there when running. The Lycoming gasket at the bottom of the tube is pretty thin. Some people swear by Real Gaskets https://www.aircraftspruce.com/catalog/eppages/basegasket.php

[Shadrach]

1 hour ago, Teddyhherrera said:

Flew her this morning and really leaned her out over about an hour. Take off power was definitely there and everything seemed better than it had ever been. I was running way too rich. I still have a blowby problem but nowhere near as bad as I had thought. I pulled the lug and it was barely wet. In my inspection, I also noticed the dipstick housing was a bit loose and leaking a small amount from the base. Fixed also. I will continue to monitor the situation.

You keep saying that you have a blowby problem, but none of the symptoms that you describe indicate a blowby problem.

[Ragsf15e]

47 minutes ago, Shadrach said:

You keep saying that you have a blowby problem, but none of the symptoms that you describe indicate a blowby problem.

I agree, he doesn’t have a blowby problem, he’s got an air cooled lycoming  aircraft engine!

[Teddyhherrera]

48 minutes ago, Shadrach said:

You keep saying that you have a blowby problem, but none of the symptoms that you describe indicate a blowby problem.

That's what my a&p said. Am I describing symptoms of another issue?

[Teddyhherrera]

7 minutes ago, Ragsf15e said:

I agree, he doesn’t have a blowby problem, he’s got an air cooled lycoming  aircraft engine!

Man, if my only problem is that I'm not running it lean enough then I'm happy to be wrong!

Edited October 25 by Teddyhherrera