Question Do you check the oil suction screen during oil changes?

[Neal]

A friend sent me this video which I posted before and it outlines not only your typical oil change but also checking the suction screen. Fess up, did you know about this? Do you do it? If you do check it, at what interval?

I can say when I observed the oil change done at 10 hours by CubCrafters back in 2021, it was not mentioned or checked, nor my 35 hour oil change done by TacAero in 2021. I'm no A&P as you know so a lot of learning going on and this is something new to me.

I'll have to check on my plane if the lower cowl has to come off to do this, my guess is yes, and that's not something I want to do at my oil change interval which is ~25 hours. I can see doing this at a 100 hour interval or at the annual condition inspection.

The video below is timestamped to take you right to the suction screen discussion. Does anyone know the part number for the gaskets needed for a Lycoming IO-360 and the torque value? I haven't searched the manual yet. I did a search and found the IO-360 parts catalog (attached) and it looks like the item is on page 27 (as on the document) and shows a 1 inch ID. This appears to be the item at Aircraft Spruce.

MS35769-21 Gasket | Aircraft Spruce

MS35769-21 Gasket AN900 (MS35769) annular copper-asbestos gaskets are suitable for temperatures up to 500 F. and pressures up to 200 PSI. Ring width is 1/8

www.aircraftspruce.com

 

[Neal]

I’m told my cc363i engine is not the same setup as the one in the video and it’s more involved such as removing the sump on and on. Not something I’m going to do but will see if at some point in time it should be done by a professional.

 

[Waldom]

I check the oil screen at every oil change, but my situation is a bit different. I am changing the oil on a Continental C90-8 which does not have an oil filter. The only filter media oil passes through in this engine is the oil screen.

By the way, I change my oil at 25 hour intervals as well. If I was maintaining an engine with an oil filter, however, I would change it at 50 hour intervals. If the filter is relatively clean, I would not necessarily check the oil screen. My reasoning is that a filter would trap and hold smaller and consequently more contamination particles than the oil screen. Of course, the filter has to be opened and checked at every change interval. I would consider extending checking the oil screen to annual inspections.

The oil screen is located upstream of the filter. It traps larger contaminants, which will naturally not show up in the filter. My reasoning for not inspecting the screen at every change interval is that if there are large particles trapped in the screen, there will surely be a significant amount of smaller particles found in the filter media. Finding this situation in the filter would necessitate checking and cleaning the screen during your investigation of the problem.

If you're maintaining an airplane in the standard [not experimental] category, there is another consideration. If the OEM maintenance manual specifies checking the oil screen when the oil is changed, you don't have the luxury of checking it at your discretion.

 

[Neal]

By the way, I change my oil at 25 hour intervals as well. If I was maintaining an engine with an oil filter, however, I would change it at 50 hour intervals.

I've heard the phrase "oil is the cheapest thing you can put into your plane (or engine?)" so I don't mind doing it at 25'ish but if I'm going on a cross-country or something it will wait until return. I think 50 is the typical interval, some do 30-35, being a new plane and me babying it I'm going with 25 for now, may extend later.

 

[Waldom]

25 hour intervals can't hurt the engine. There are certainly more contaminants (mostly carbon and lead) suspended in the oil at 50 hours than at 25 hours of use.

By the way, the cheapest thing I put in my airplane is me.