As an airplane owner, you are probably at least somewhat familiar with the task of cutting open the oil filter at an oil change.

It’s a routine part of airplane oil change.

But what should you look for, and how do you know when to be concerned?

In today’s episode, we discuss an issue that came up just the other day, that may end up requiring this engine to be removed for a teardown inspection.

Here’s what was found in this particular oil filter:









Perhaps you know right away what that orange stuff is.  If not listen to today’s episode to hear about it.

This filter came from an experimental airplane with a Lycoming engine on it.

This whole deal reminded me of an article that Mike Busch wrote for the April 2013 edition of Sport Aviation magazine, called “A Little Dab’ll Do Ya – In.”

In that case, some gasket-maker on a cylinder base was a factor in a Beech Debonair crash landing in a vineyard.

You can read this article here:

So, what can we learn from stories like this?

Here are a few things:

  1. Take a look at your engine and make sure you don’t have any silicone or gasket-maker that has been squeezed out between the cylinder bases and the crankcase, or between the crankcase halves.  Not sure what you’re looking for?  Check with your A&P.  (The cylinders need to be installed with all surfaces totally clean, with a new cylinder base o-ring, lightly lubed with the proper engine oil.  The crankcase halves need to be installed per the overhaul manual instructions, and not with any silicone or gasket-maker.)
  2. When you have a cylinder removed and reinstalled, make sure no silicone or gasket-maker is used at the cylinder base… just a new o-ring with the proper oil on it.
  3. When you have your engine overhauled, make sure no silicone is used between the crankcase halves, or in any other places it should not be.
  4. Be vigilant and keep learning.

Finally, I want to encourage you to check out this new podcast by Adam Sipe and Don Sebastian:

It’s called the “Airplane Intel Podcast” and you can find it on iTunes, and at

Let them know you heard about it on Airplane Owner Maintenance.