Oil Change frequency for turbocharged Mooney

[gsxrpilot]

1 hour ago, alextstone said:

They probably burn so much oil that they actually after in the progressive oil change program

Hey, that's the program I'm on 

1 hour ago, kpaul said:

Ok, so folks are saying if you change your oil, change your filter even if you do it at 25 hours.  But, I also see anywhere from 25 to 30 to 50 hours. I change both every 30 hours.

Playing devils advocate,  how is it acceptable to change both at 50 hours, and not acceptable to change the oil but not the filter at 25 hours?

The thought here is that you're only doing 7/8th's of an oil change. 7 quarts of new oil and one quart of old dirty oil. 

[PT20J]

14 minutes ago, Jerry 5TJ said:

Nobody knows.    Consensus is -- change both oil and oil filter frequently.

Yep. Lot's of opinions, but I've never seen any detailed studies with actual data. Since one of the often expressed concern is acid buildup, it would be interesting to take samples every ten hours and send them to Blackstone for a TBN analysis.

Skip

[Unit74]

Lycoming recommends 50 hours Lance. Doing a oil filter swap mid cycle has zero value in my opinion. A dump and pour does have value. That’s my opinion, and I am satisfied with it. I was doing filters at 25 for a while and saw no value in it upon inspections. APs concurred that a 25 hour filter is excessive unless you just want to feel good about it on a healthy engine. My current mechanic runs a very successful and busy shop, and builds engines as well. I trust their opinions, not necessarily internet conjecture.  

 

 

[Bentonck]

Guys, sorry for my parachuting into the middle here.  As you know, all new to me.  I used to swap my 172 at 50hr as designated in the POH.  I read through the M20T POH and it calls for 50 hour changes as indicated in the text above, but it seems that everyone is ignoring that and changing at 25 hrs.  I ran back through the logs and it looks like the previous owner was changing every 50.  (He was flying the plane 200 hours a year the last two years so this was every 3 months or so, his usage was pretty linear as his business (as mine) is far from "home") ... 

So I have read through the discussion and noone is advocating 50 hr changes, the discussion is whether or not you change the filter at 25-30 hours when you change the oil.... (from my days of hotrodding 4x4's the argument was that if you are going to spring for oil why would you leave a dirty quart in there?  Although in our engines there is always a couple of residual quarts in the oil cooler and prop hub that you can't drain anyway, but if I am changing the oil, a new filter is going on too) ...so how did everyone land on the 25-30 hr oil change as a necessity if I can back up and ask?

Thanks...

[spectre6573]

My opinion is it depends on the how much the aircraft is flown. For instance, If you are a 100 hour a year person then 25 hours might make a lot of sense. However, if you are somebody that does 20-40 hours a month average, then 50 hours could make more sense. 

[carusoam]

Advantages and disadvantages...

1) Change filter early... 

2) change oil early...

3) Change filter late...

4) Change oil late...

 

Oil suffers from at least three challenges...

5) it is in charge of collecting all kinds of dirt and wear particles.... suspended in the oil...

6) it is constantly losing viscosity while in contact with very hot parts of the engine... turbos and exhaust valves are really hot... above the breakdown temperature of the oil...

7) Acids from the exhaust products also help with breaking the oil chains....

8) Exhaust by-products can be minimized by having good healthy rings, and operating LOP...

Changing out the oil...

9) It is best to do a complete oil change... because leaving a quart of old oil in with the new.... doesn’t have a linear relationship... on the break down of viscosity... even then there is a quart of oil left in the engine... prop and oil cooler...

10) acids in the oil aid the break down of oil... starting with fresh oil is a nice way of starting with no acid in the oil...

11) when it comes to recommendations from the manufacturers of the engine... This is a tough call... expect their recommendation to say the engine will last forever, with one oil change at the halfway point... know that you are the official bag holder... the one left holding the bag...  

12) I liked the recommendation (Piloto) to rinse the sump out with gasoline... but, the inherent unknown additional risk is too much for me...

It is really cool having access to a lab that can test viscosity... being able to graph the breakdown of viscosity over time is really helpful...  unfortunately, trying to do this with one data point and a myriad of other variables is highly unlikely to get Much useable data...

For home use... if you have a nicely heated hangar with great temp control... a simple viscosity test is timing a metal ball falling through a glass tube... a few CCs of oil is all it takes to get a go /  NoGo decision...  temp of the lab will effect the test...

+1 on Jerry’s input... plus a couple of added details...  We can’t tell, nobody knows, engine folks May over estimate, change both early and often...

TC’d engines are more susceptible to the heat challenge for their oil...as the oil has much more contact time with very hot metal surfaces... acids will exacerbate the challenge...

Fortunately we have a bunch of real world experience on MS to have a good grasp of what works...

Thanks for sharing your experience...

PP thoughts only, not a mechanic...

Best regards,

-a-

[alextstone]

The answer for Lycoming oil and filter change intervals is on page 2 of the attachmenthttps://cloud.tapatalk.com/s/5ea87a2c0a677/SB480F%20Oil%20ServicingMetallic%20Solids%20Identification%20After%20Oil%20Servicing%20and%20Associated%20Corrective%20Action.pdf

Sent from my Pixel 3 XL using Tapatalk

[carusoam]

Livened up the link above...

-a-

https://uploads.tapatalk-cdn.com/files-2178/1588099627_SB480F20Oil20ServicingMetallic20Solids20Identification20After20Oil20Servicing20and20Associated20Corrective20Action.pdf

[kortopates]

10 minutes ago, Bentonck said:

Guys, sorry for my parachuting into the middle here.  As you know, all new to me.  I used to swap my 172 at 50hr as designated in the POH.  I read through the M20T POH and it calls for 50 hour changes as indicated in the text above, but it seems that everyone is ignoring that and changing at 25 hrs.  I ran back through the logs and it looks like the previous owner was changing every 50.  (He was flying the plane 200 hours a year the last two years so this was every 3 months or so, his usage was pretty linear as his business (as mine) is far from "home") ... 

So I have read through the discussion and noone is advocating 50 hr changes, the discussion is whether or not you change the filter at 25-30 hours when you change the oil.... (from my days of hotrodding 4x4's the argument was that if you are going to spring for oil why would you leave a dirty quart in there?  Although in our engines there is always a couple of residual quarts in the oil cooler and prop hub that you can't drain anyway, but if I am changing the oil, a new filter is going on too) ...so how did everyone land on the 25-30 hr oil change as a necessity if I can back up and ask?

Thanks...

Its not just hours on the oil but also calendar time since oil becomes corrosive from blow-by contaminants. Most of our engines die prematurely from corrosion - not wear.  Also keep in mind our engine manufacturers recommendations on oil change intervals  have nothing to do maximizing engine longevity. Both Lycoming and Continental provide the same general recommendations to change the oil every 50 hrs if you have a oil filter and every 25 hours if you don't have an oil filter (just screen), regardless of what kind of engine or size. But their recommendations aren't nearly as concerned as we are with wanting to get to at least TBO if not beyond many years after the original OEM  warranty expired (which is only 2 yrs for both new Lyc and Continentals).  

Putting calendar time and hours together, a good common sense  approach to oil change intervals for airplanes flow upto 150 hrs a year is to change the oil every 4 months (or 3x a year) with up to 50 hrs at at time. If your flying more than that, such as 200 hrs a year, then every 3 months or 4 times a year will provide the added protection. But for the larger group of owners that are flying 50-100 hrs a year the 3x a year change will result in oil changes every 25-35 hours and every 4 months which will help reduces the corrosive properties of the oil. 

Its also fine to go a bit high in hours when you are frequently flying and accumulating hours higher than normal, such as on a long trip, and then change the oil the right after yiuy return and before it will be sitting after your trip. i.e. you also want to to maximizing the time your engine is sitting in clean oil rather than corrosive dirty oil as you divide up your calendar time between oil changes. But your not going to go wrong changing it every 25-30 hrs regardless as long your also not exceeding calendar time of about every 4 months. And in fact Ed Kollin from Camguard would recommend exactly that.  But key here is that calendar time is just as important as engine hours due to the corrosive nature of dirty oil. If you really want to back that up with some scientific proof so to speak you can ask the Blackstone folks to analyze  your oil for the TBN - Total Base Number test. Virgin fresh oi will have a TBN of around 10, but by the time it decreases to 2 or 3 its losing its ability to neutralize acids and should be retired. 

This is all covered in Chapt 39 in Mike B Engines Book or also readable from the AOPA link I posted above earlier: https://blog.aopa.org/aopa/2017/02/24/why-change-the-oil/

[LANCECASPER]

6 hours ago, Unit74 said:

Lycoming recommends 50 hours Lance. Doing a oil filter swap mid cycle has zero value in my opinion. A dump and pour does have value. That’s my opinion, and I am satisfied with it. I was doing filters at 25 for a while and saw no value in it upon inspections. APs concurred that a 25 hour filter is excessive unless you just want to feel good about it on a healthy engine. My current mechanic runs a very successful and busy shop, and builds engines as well. I trust their opinions, not necessarily internet conjecture.  

 

 

It's nice that you trust him, but I would trust him more if he actually looked up on the internet the Lycoming Mandatory Service Bulletin 480D (and newer)  that 20 years ago updated the oil change interval for the TIO-540-AF1A and the TIO-540-AF1B, which are the only two Lycoming turbo-charged engines in Modern Mooneys, to every 25 hours. I prefer that instead of following old mechanic's conjecture.

I wonder what else he's missed in that last 20 years.

[PT20J]

47 minutes ago, LANCECASPER said:

It's nice that you trust him, but I would trust him more if he actually looked up on the internet the Lycoming Service Bulletin 480D (and newer)  that 20 years ago updated the oil change interval for the TIO-540-AF1A and the TIO-540-AF1B, which are the only two Lycoming turbo-charged engines in Modern Mooneys, to every 25 hours. I prefer that instead of following old mechanic's conjecture.

I wonder what else he's missed in that last 20 years.

And, don't forget the SB requires pulling the suction screen every oil change also.

[larryb]

I change oil and filter at 25 hours. But I have done a few cross-USA trips where I do 40 hours in 3 weeks. And on those extended intervals my oil analysis is always good.

On the question of the filter I always do it in my K. It has an upside down mount and holds a quart of dirty oil. But on the lycoming io360 the oil drains out of the filter so if you change it a day after flying there is no dirty oil left over. So a few times I did skip the filter with that engine if I was busy and needed a quick change. This question really depends on which motor you are discussing.

[Unit74]

Fair enough Lance. I was unaware of the Mooney-specific requirements. I fly a TIO-540 S1AD. Is there something specific about that engine triggering the reduced filter changes?

[LANCECASPER]

7 hours ago, Unit74 said:

Fair enough Lance. I was unaware of the Mooney-specific requirements. I fly a TIO-540 S1AD. Is there something specific about that engine triggering the reduced filter changes?

Good question. It is a hot running engine - my guess is that they noticed that the oil breaks down faster. Plus 18 or more gallons of fuel an hour go through the engine perhaps leading to a higher lead count. The Service Advisory doesn't spell it out.

One way this engine oil picks up extra heat is that the -AF1B engine is a "wet-head" engine, meaning that it has oil lines on top of the cylinder heads pushing oil down a channel near the exhaust valves (or the hot section of the engine), wicking away heat. The updated exhaust valve guides are unique to this engine and very expensive.

Lycoming was having all kinds of warranty problems with this engine early on (1989-1995) and to their credit they addressed a lot of the problems and ended up with an engine that now makes it to TBO if flown and maintained diligently. The TIO-540-AF1B now also stands a really good chance of making it to TBO without cylinder changes, not so much with the Continental turbo-charged engines. Ironically not long after Lycoming got the engine all sorted out, Mooney took the M20M out of production in favor of the Acclaim (Continental TSIO5550 engine). Maybe it had been in the works for awhile while Lycoming was sorting through their crankshaft recall in the early 2000's.

And sorry for going off a little in that last post. TLS Bravo airplanes (M20M) change ownership and new owners are told by well-meaning friends and mechanics that 50 hour oil changes are ok for that engine. For whatever reason, and they must have one, Lycoming says 25 hours specifically for that engine.

Surprisingly your TIO-540-S1AD is more expensive that the TIO-540-AF1B. It does produce 300 hp compared to 270 for the Mooney. It would be interesting to know why Lycoming recommends it for one engine and not the other.

 

 

[jlunseth]

I vary my oil change frequency depending on how much I am flying.  There have been times when I would do 25 hours in about two weeks, and times when it takes months to do it.  When I am flying very actively I will let it go to 50 hours, when I am not so active I change at 25. Lots of reasons for it.  When the engine is being operated regularly any moisture in the crankcase gets boiled off regularly. On the other hand, especially if its winter and the engine is sitting and sometimes getting heated, pretty easy to build up moisture in the crankcase that sits. I worry more about moisture build-up and the oil draining off all the metal leaving it exposed, than I do about a modern engine oil breaking down in as little as 25 hours, or even 50 hours. I always have the filter changed but that’s just me.  Changing a filter is not much of a chore and splitting them frequently gives me a faster read on the condition of the engine. I have settled in on Phillips XC, seems to hold up, keeps the engine in good condition. I have practically no oil burn in my TSIO360LB. I generally don’t need to add if I change at 25 hours, I lose a quart or less.

[Bravoman]

Oil and filters are cheap. 25 hrs max in anything I fly.  I run Mobile One in my vehicles and change that every 3000 miles, and mechanics think I am crazy. Maybe so, but it makes me feel good.

[alextstone]

I have you all beat...I just changed the oil AND the filter on my Bravo after 9 hours flight time...of course, I did just change the #5 cylinder due to a burnt valve.  Overkill?  I think not.  I like the fact that I KNOW there were no visible metal shards in the filter and the oil is fresh and clean after a couple of hours of break in for the new cylinder.  

[FloridaMan]

Fellow rocket owner here. I do it every 50 hours or four months. Your consumption sounds about right. 

[donshapansky]

I flew a 1988 252 Rocket for 1,000 hrs. in a 4 yr. period. I had lost a camshaft in the previous aircraft, which was an IO-520 (Bellanca Super Viking). Both aircraft were flown weekly with the same care. I used oil analysis with every change (30 - 40hrs.) and cut the filters open at every change. Using a magnet on the paper to look for iron particles. I never had any indication of the camshaft failure prior to the actual event, which turned out to be the loss of the stellite material on the tip of the hydraulic lifter. The EDM showed it immediately with a loss of EGT on No. 5. The cheat sheet I carried identified the problem precisely. The camshaft lobe was destroyed of course, that resulted in a bottom overhaul with only 590 hrs. SNEW

After that failure I had read about Camguard and met the designer at Oshkosh and started to use it at every change with Phillips 15W50 all year, due to living in Texas. The Mooney had 50 SMOH when I bought it, it had ECI NIKISIL cylinders, over time the leak downs stayed in the 70's but the oil began to darken much sooner and it started to use a little bit of oil at about 500 hrs. Maxwell did all the oil changes and all the maintenance. At the next annual I decided to have the cylinders removed (750 hrs. SMOH) due to the oil getting dark. The overhaul guys in OK thought based on what I told them that I should not remove the cylinders, when they got the cylinders they called me to say that I was right to pull them. Three cylinders had stuck rings and several valve guides were worn beyond limits. The cylinders were in perfect shape, no taper and no out of round.

When we reassembled the engine we put an air/oil separator on and then I could run 11qts. without blowing it out. The oil stayed clean, I could then run LOP without exceeding 1650F TIT. The oil stayed golden right to oil change time and the oil samples came back perfect every time. My experience made me realize the value of cutting filters open and doing oil analysis. I flew in the rocks a lot and at night when I had to, after losing a turbo one evening at 17,500 with a forced approach into Santa Rosa, I lost my appetite for single engine at night in the rocks.

The air/oil separator saved the engine on the forced approach, because I was running 11qts. The time from loss of boost to landing was 12 minutes, it had blown out 8qts. in that time!

 

  

[Schllc]

When I was about 12 I recall talking to my uncle, who was an eclectic fella in the 1970’s, I remember him telling me about sending in oil samples because he was participating in a study for synthetic oil testing for cars, and had been for years.  He explained to me that the 2500 mile auto change was unnecessary, and he was going 10-15k between oil changes. 
not sure why this stuck with me, but it did, and when I bought my first new Toyota truck in 1987, i went 15k between changes. I put over 200k on that truck.  
Since then I have owned around 50+ vehicles of my own, and for my company over 35 years, and I would guess logged over  10 million miles in all those (not just me driving obviously), all with the same oil change regiment.
Mostly Toyota and GM, with a few fords and Isuzu’s, and one Mercedes sprinter, gas and diesel. 
I have never once had an engine failure, or required a rebuild, and almost all of those vehicles saw 200k mikes before I sold or traded them, a few over 300k and one with 500k that I still own.  

Somewhat anecdotal, but I have noticed most maintenance items with planes are already excessively conservative, given the consequences of failures it’s difficult to argue that bent...

My point is I believe oil change guidelines are predicated on the worst possible conditions, at all times, which is seldom the case. 
That being said, more frequently can’t possibly hurt. 

[201Steve]

io360 here. I whole heartedly believe the oil filter could easily go 100 hours. It holds 1/4 quart maybe when cold. I would  put good money on zero difference in an otherwise identical lifetime comparison with one changing filter every swap, and one changing filter every 2 or 3 swaps. With a quick drain valve, it wouldn’t even need to be de-cowled and you could change just the oil in 5 minutes of labor. That said.... it’s my airplane and I enjoy treating it like a baby,  so I change it with the oil.

[kortopates]

2 hours ago, Schllc said:

When I was about 12 I recall talking to my uncle, who was an eclectic fella in the 1970’s, I remember him telling me about sending in oil samples because he was participating in a study for synthetic oil testing for cars, and had been for years.  He explained to me that the 2500 mile auto change was unnecessary, and he was going 10-15k between oil changes. 
not sure why this stuck with me, but it did, and when I bought my first new Toyota truck in 1987, i went 15k between changes. I put over 200k on that truck.  
Since then I have owned around 50+ vehicles of my own, and for my company over 35 years, and I would guess logged over  10 million miles in all those (not just me driving obviously), all with the same oil change regiment.
Mostly Toyota and GM, with a few fords and Isuzu’s, and one Mercedes sprinter, gas and diesel. 
I have never once had an engine failure, or required a rebuild, and almost all of those vehicles saw 200k mikes before I sold or traded them, a few over 300k and one with 500k that I still own.  

Somewhat anecdotal, but I have noticed most maintenance items with planes are already excessively conservative, given the consequences of failures it’s difficult to argue that bent...

My point is I believe oil change guidelines are predicated on the worst possible conditions, at all times, which is seldom the case. 
That being said, more frequently can’t possibly hurt. 

There is certainly much truth in your assessment above. For one our aircraft engines are operating at a higher % horse power on average much above what we operate a vehicle at.

But more importantly it just not fair to make a comparison between an auto engine running on unleaded gas that is water cooled allowing it to operate at much tighter tolerances with much lower viscosity oils and with much less blow by contaminating the oil. Our Air cooled engines with much looser tolerance to allow for much greater thermal expansion run much dirtier from both the higher blow by and from our leaded gas.  A clean running auto engine can run on synthetic oil easily for 10-15K miles and that synthetic oil is still doing great since the polymers making up the synthetic oils are made of giant molecules that don't have all the side branches of mineral oil molecules that shear in use. The shearing causes mineral oil to break down much quicker than polymers that are much more resilient. But the problem is that synthetic oils are a poor choice for our leaded gas burning engines since they aren't as good at holding particulate contaminants in suspension like pure mineral oil can. Unfortunately, that's what makes the most popular multi-weight oil by far, which is 50% synthetic (Aeroshell 15W-50) a poor choice. Straight weight 100% mineral oil is better choice and for those that do need a multi-weight, Phillips XC 20W-50 which is also 100% mineral oil.

But the bottom line is our AC engine oil change interval is not a function of the oil breaking down but from the oil getting dirty with corrosive contaminants. After all, our engines die much more from corrosion than wear. See the following paper for much more detail on the topic:

Reference: https://resources.savvyaviation.com/wp-content/uploads/articles_eaa/EAA_2011-01_all-about-oil.pdf 

Edited April 30, 2020 by kortopates

[Schllc]

I had read that article some time ago, very good explanation. 
I understand comparing automobiles is not completely apples to apples, which is why I said it was anecdotal. 
I have also followed the guidelines for oil changes with and without a turbo on the three I have owned. It’s just not worth saving $200 to see.

My point was merely for reflection because while I know a car engine burns much cleaner, for a 15k oil change at an average of 30mph is 455 hours.  So does the airplane engine run 18x dirtier than an automobile?  Perhaps..

the conclusion of the article was also interesting, stating that the vast majority of damage from the corrosive elements was due to inactivity, not simply their presence in the oil. 
I took this to heart, and always purchased planes that had been regularly flown. 
In fact it’s been the biggest reason I haven’t been able to find my Aerostar, almost all of the ones I’ve seen fly 3-10 hours a year. That scares me a lot more than oil change intervals.

[Danb]

A few mentioned their oil was golden when they changed the oil. Now I’m wondering if I have an issue, my oil gets quite dark, it’s black when I change it at 25 hours, why could that be. I’ve been told I most likely run it to rich, if so after 1000 hours on the engine would it be beneficial to run lean?

[alextstone]

35 minutes ago, Danb said:

A few mentioned their oil was golden when they changed the oil. Now I’m wondering if I have an issue, my oil gets quite dark, it’s black when I change it at 25 hours, why could that be. I’ve been told I most likely run it to rich, if so after 1000 hours on the engine would it be beneficial to run lean?

@Danb, I causally noticed that too.  I'd have to read back over the thread but I think those who claim this mystery oil virginity are not flying Bravos - fact check me on this if you have the time.  Perhaps the "dirty little secret" of our engines is that they are inherently leaky beasts running in extreme conditions and thus the special requirement to change the oil (and filter) every 25 hours.  At the end of the day, oil analysis is your friend.

 

BTW:  I run LOP with some regularity and I have not noticed a difference.