Change oil now, or after trip?

DesertNomad

DesertNomad

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DesertNomad
I have normally changed my oil after 35-40 hours on my Dakota since I bought the plane six years ago

I have 29 hours on my oil right now and have added three quarts in those 29 hours. These are all XC hours - Reno to St. Louis, Texas and back.

This week I need to fly Reno to Ohio and back. It will be at least 20 hours of flying. Should I change it now before I go? I could change it in Ohio, but the weekend may interfere with that and I don't have any know shops in the area there.
 
6 hours early or 9+ hours late? One vote for changing it now.
 
:yeahthat:

Plus, if you change it now you'll probably have to add less during the trip, since new oil burns slower.
 
Fine. I'll play devil's advocate. I change my oil at 50 hours. My oil samples come back very clean with all my numbers very close to Blackstone's universal averages and the viscosity still well within spec. In the situation you describe I'd probably change it when I got back. I'm not going to lose any sleep going a little over 50. If I thought I was going to hit 60 I'd probably find a shop on the road to do it.
 
DesertNomad said:
I have normally changed my oil after 35-40 hours on my Dakota since I bought the plane six years ago

I have 29 hours on my oil right now and have added three quarts in those 29 hours. These are all XC hours - Reno to St. Louis, Texas and back.

This week I need to fly Reno to Ohio and back. It will be at least 20 hours of flying. Should I change it now before I go? I could change it in Ohio, but the weekend may interfere with that and I don't have any know shops in the area there.
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Oil consumption of 1 qt <10 hours seems a bit much for an O540-J3C5D. Do you have guide wear on #5 cylinder?
 
Jim K said:
Fine. I'll play devil's advocate. I change my oil at 50 hours. My oil samples come back very clean with all my numbers very close to Blackstone's universal averages and the viscosity still well within spec. In the situation you describe I'd probably change it when I got back. I'm not going to lose any sleep going a little over 50. If I thought I was going to hit 60 I'd probably find a shop on the road to do it.
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I'm with you. OP is already changing the oil 10-15 hours earlier than recommended, and is now considering changing even earlier. It's fine if you want to, but where does it stop? Why not change it every 20 hours? 10?
 
20 hours of flying, at 75%, will be about 15 hours on the tach. I say a vote for "later".
 
I’d probably change it now, but honestly it won’t a hurt a thing to wait til you get back. I’ve tried to change the oil in the Archer around 40hrs, but I’ve also ran it to 50 if I couldn’t get it done before.
DesertNomad said:
I don't have any know shops in the area there.
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Bring the tools and change it yourself? :)
 
A wise man once told me that the two cheapest things you will ever buy for your airplane are oil and gas. ;)
 
Clip4 said:
Oil consumption of 1 qt <10 hours seems a bit much for an O540-J3C5D. Do you have guide wear on #5 cylinder?
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I had #5 stick open four years ago and it resulted in an emergency landing. It never lost power and the landing was uneventful. Everything has looked good since after doing Lycoming's 400 hour valve service. I probably only needed to add 2 quarts but it is hard to tell the oil level immediately after flying and I added a quart yesterday enroute from TX to Reno. I try to keep it between 9 and 10 quarts. It has 10 in it now.

Why do you mention #5 specifically - because that tends to be the hot one due to the oil cooler location?

The engine is a O540-J3A5D. I would guess over the six years I have had the plane and 700 hours, the oil consumption is about one quart per 10 hours.
 
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I would change it when you get back. Many change oil at 50 hours including myself.

Last year I ran the oil in a 0-320 motor to 100 hours because I was going to replace the motor.
I sent a sample of the 100 hour oil to blackstone. The said it was well within averages and no problems detected.

I fly way too much to do 25-30 hr oil changes. If I did them that often I would sped more time changing oil than flying the plane. This is the reports for my new motor.
(edited)_IMG_1080.JPG
 
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I didn’t see mention of TIME since the last oil change? That’s another factor into the decision, though it does sound like mostly cruise hours over a shorter period.
 
sourdough44 said:
I didn’t see mention of TIME since the last oil change? That’s another factor into the decision, though it does sound like mostly cruise hours over a shorter period.
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It was changed about 6 weeks ago at annual.
 
DesertNomad said:
I had #5 stick open four years ago and it resulted in an emergency landing. It never lost power and the landing was uneventful. Everything has looked good since after doing Lycoming's 400 hour valve service. I probably only needed to add 2 quarts but it is hard to tell the oil level immediately after flying and I added a quart yesterday enroute from TX to Reno. I try to keep it between 9 and 10 quarts. It has 10 in it now.

Why do you mention #5 specifically - because that tends to be the hot one due to the oil cooler location?

The engine is a O540-J3A5D. I would guess over the six years I have had the plane and 700 hours, the oil consumption is about one quart per 10 hours.
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My experience with the O540 is #5 doesn’t cool as well as the rest and valve guide wear occurs and oil starts bypassing. If you do your own plug maintenance you may notice oil on the lower #5 spark plug as the engine adds hours. The same thing happens on the 1978-79 182RGs that have a front mounted il cooler.
 
Dana said:
I have always found that the oil consumption rate increases as the oil ages, I have to add oil more often as I get closer to the next oil change. Many others report the same thing.
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Has been my experience as well.
 
Dana said:
I have always found that the oil consumption rate increases as the oil ages, I have to add oil more often as I get closer to the next oil change. Many others report the same thing.
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I also have noticed that.
 
Dana said:
I have always found that the oil consumption rate increases as the oil ages, I have to add oil more often as I get closer to the next oil change. Many others report the same thing.
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I have not found that, but I normally change oil at 25 hours and I have an oil filter.
 
This whole idea that you need to "change" oil is a scam. The oil was created millions of years ago - mostly in the Mesozoic age. Dozens or hundreds of hours one way or the other can't possibly make any difference.
 
for well and often running engine, I would change it after I get back.
 
I went through a similar analysis recently. Was 10 hours from an oil change with a ~20 hour trip on the horizon. I waited till after. 10 hours isn't going to make any material difference, partially due to finding time to do the change. Plus, there's a little bit of "it's running fine, don't **** with it till after the trip" mentality.
 
and if you plan it right....you'll save a quart of oil by letting it burn down...when changing after the flight. A few hours won't make a difference in your engine wear.
 
If it’s going to sit idle…change the oil so the engine doesn’t bath in dirty oil, do this before maintenance jobs that may take weeks (paint, avionics, etc) as well. If it’s much earlier than normal you can skip replacing the filter.
 
MooneyDriver78 said:
If it’s going to sit idle…change the oil so the engine doesn’t bath in dirty oil, do this before maintenance jobs that may take weeks (paint, avionics, etc) as well. If it’s much earlier than normal you can skip replacing the filter.
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you do realize the oil pan.....is below all the parts that need the oil. It's not gonna be in a bath....unless it's running in which case it's getting a spray bath.
 
Checkout_my_Six said:
you do realize the oil pan.....is below all the parts that need the oil. It's not gonna be in a bath....unless it's running in which case it's getting a spray bath.
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It’s going to be coated in dirty oil. Of course you need to test run after changing the oil, but I assume this is SOP.
 
MooneyDriver78 said:
It’s going to be coated in dirty oil. Of course you need to test run after changing the oil, but I assume this is SOP.
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Just signed off my annual. The oil was changed a few weeks ago.....guess what? I'll run it for the first time tomorrow. ;)


...so, it's still coated with dirty oil. o_O
 
I'm in the "who cares" camp. Do it whenever it is most convenient for you. It's not like the oil suddenly gets "dirtier" 25 or 50 hours or whatever.
 
a few have suggested to change the oil, but not the filter and change it next time. the other threat @Salty mentioned, i see some of you suggested that as well. while I never did that, i am wondering what the de-merits are in doing that? I have been changing oil (and filter) at 29-30 Tach since i got the plane, but wondering about this method of changing the oil at 25 hours and both the oil and filter at 50 hours
 
WannFly said:
a few have suggested to change the oil, but not the filter and change it next time. the other threat @Salty mentioned, i see some of you suggested that as well. while I never did that, i am wondering what the de-merits are in doing that? I have been changing oil (and filter) at 29-30 Tach since i got the plane, but wondering about this method of changing the oil at 25 hours and both the oil and filter at 50 hours
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I think it’s overkill, but it’s easy.
 
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