Oil Filter Change at 25 or 75 Hours?

hish747

hish747

Pre-takeoff checklist
Joined
Mar 31, 2015
Messages
247
Location
Skylark Airpark
Display Name
Display name:
Hish747
I bought the PA28-140 in July. As part of the pre-purchase inspection, I had the oil filter cut open, inspected and replaced. At that point the oil had 25 hours on it and wasn't changed. Oil analysis and filter looked great. I have since put another 25 hours on the plane and am ready to change the oil. The question is, do I leave this filter (that only has 25 hours on it) until the next oil change or do I change it now?

I tend to think leave it until the next time because if it's clean at 25, that's not much of an assurance because not enough time for stuff to appear. On the other hand, if it's clean at 75 hours, that would be a great sign.

What do you guys think?
 
I change my oil at 25 and my filter at 50. I could extend the oil to 50 but the calendar usually dictates a shorter interval for oil. Your engine manual may provide for 50 hours for the fiter but I’ve never seen 75 hours allowed.
 
Change them both at the same time. This way when something turns up you have a better idea of when it happened. The cost difference is minimal when you're already in there and you'll be a pro with safety wire before you know it.
 
I change them both every 25 hours and have the oil analyzed. As Ravioli says, this will tell me when a problem began and allow me to catch it sooner if a problem does develop. It also keeps me from having to add oil between changes.
 
We always change both, just for a data point. We shoot for 25 and sometimes go over if life gets in the way. I think we are pushing our longest ever at 39 right now. Annual next week so we’ll let the shop change it and check it all this time. Timing just worked out that way.
 
JOhnH said:
I change them both every 25 hours and have the oil analyzed. As Ravioli says, this will tell me when a problem began and allow me to catch it sooner if a problem does develop. It also keeps me from having to add oil between changes.
Click to expand...

Me too. In my case it is more of an elapsed calendar time on the oil issue, 25 hours is about 6 months for me (sometimes a bit less).

Steve
 
Change both oil and filter at 25 hours, cheap insurance, and good monitoring information. Why would you want to contaminate new oil with a qt. of old oil in the existing filter?
 
NavAir said:
Me too. In my case it is more of an elapsed calendar time on the oil issue, 25 hours is about 6 months for me (sometimes a bit less).

Steve
Click to expand...
This is what works for me as well...and because the POH say change every 50 hours, I don’t worry if I go over every now and then to 30 hours or so (although I won’t go over 6 months).
 
GlennAB1 said:
Change them both. You want as much old oil out of the engine as possible at oil changes.
Click to expand...

That

It's like taking a shower to wash off only to use a filthy towel

I change mine at 50hrs per the book, unless calendar occurs first or the oil gets really dark on the dipstick.

Always cut my filter, but oil analysis, just don't get enough out of it to bother anymore.
 
25 hrs is the number I use. Oil change today if I get off my butt....:rolleyes:
 
hish747 said:
I bought the PA28-140 in July. As part of the pre-purchase inspection, I had the oil filter cut open, inspected and replaced. At that point the oil had 25 hours on it and wasn't changed. Oil analysis and filter looked great. I have since put another 25 hours on the plane and am ready to change the oil. The question is, do I leave this filter (that only has 25 hours on it) until the next oil change or do I change it now?

I tend to think leave it until the next time because if it's clean at 25, that's not much of an assurance because not enough time for stuff to appear. On the other hand, if it's clean at 75 hours, that would be a great sign.

What do you guys think?
Click to expand...

My two cents worth:

Been hammering on these critters for thirty years. Seen a lot of engines die before their time because of the owner wanting to save a few bucks on oil changes. It's false economy that will likely result in costly repairs down the line. Clean oil is the cheapest insurance money can buy for your engine.

Remember the cost of overhauls is not cheap.
 
It has nothing to do with saving money, Norman. My question really revolves around the usefulness of the information gained from opening a filter at 25 vs 75 hours. Thanks for your thoughts.
 
hish747 said:
It has nothing to do with saving money, Norman. My question really revolves around the usefulness of the information gained from opening a filter at 25 vs 75 hours. Thanks for your thoughts.
Click to expand...
I still suggest opening the filter now, and doing an oil analysis,
then open it again next time, and do another analysis.

This way, you will see any potential problem sooner, AND you will see if it is getting worse.

I fully understand you are not looking for a way to save money. But I think closing your eyes for the next 25 hours is not an effective way of heading off potential problems.
 
JOhnH said:
I still suggest opening the filter now, and doing an oil analysis,
then open it again next time, and do another analysis.

This way, you will see any potential problem sooner, AND you will see if it is getting worse.

I fully understand you are not looking for a way to save money. But I think closing your eyes for the next 25 hours is not an effective way of heading off potential problems.
Click to expand...

If you have a filter, 25hrs is just changing the oil for the sake of changing oil, shy of very extream conditions or the plane not flying much.

50 really seems like the best number for a full oil and filter change.
 
James331 said:
If you have a filter, 25hrs is just changing the oil for the sake of changing oil, shy of very extream conditions or the plane not flying much.

50 really seems like the best number for a full oil and filter change.
Click to expand...
I agree that 25hrs might be a bit excessive, but I don't like waiting till 50, so I often slack off and go to as much as 35 or 40 hours, or 6 months max (That is when my A&P starts calling to remind me).
My main point is that I think 75 hours is too long, and I have never liked the idea of changing oil and leaving a dirty oil filter in place.
 
Thanks again everyone for your thoughts. I'll do the oil and filter together.
 
On my Cherokee I change both filter and oil every 30 hours or every 3 months, which ever occurs first. Like said before, oil is cheap compared to an overhaul. And clean oil is less corrosive than used oil. Might not be the best but that's what I do. Filter is cut open every time and oil sample sent off every time.
 
I do oil and filter,at every 25-30 hours. Has worked for me ,on all my airplanes.
 
Changed oil and filter today,2hrs. I'm happy, fly in the morning...:)
 
James331 said:
If you have a filter, 25hrs is just changing the oil for the sake of changing oil, shy of very extream conditions or the plane not flying much.

50 really seems like the best number for a full oil and filter change.
Click to expand...
There was a study (albeit on car engines) that found there were two periods that had the most wear during an oil change cycle: just before the change (when the oil is old), and unbelievably IMMEDIATELY AFTER an oil change! The study concluded that oil molecules need to be “worked over” (my term, not theirs) in an engine a bit to provide the best lubrication...the study concluded that you could theoretically cause MORE wear by changing oil more frequently.
 
Oil change and cut filter every 25-30 hrs and analysis from Blackstone labs. Pa-28 181

Sent from my SM-G935V using Tapatalk
 
I think the thing that makes the most difference between 25 and 50 hrs is how long it takes to get those hours. on a rental, at 25 hours you could be changing it every week. bit of overkill, but on some airplanes 25 hrs could be a year.

as to the original poster, just change the filter to get it back on schedule.

bob
 
You must log in or register to reply here.
Back
Top