I hate oil filters

[Colonel Sanders]

I know that I am considered something of a luddite
because I hate oil filters, almost as much as I hate
parking brakes.

Read Mike Busch's column this month. He got a frantic
call from a pilot who didn't have any oil pressure. Local
mechanic insisted on an engine overhaul. Mike recommended
checking the oil relief valve first. Sure enough, tiny piece of
aluminum had jammed it open. Was removed, engine
ran fine. But where did the metal come from?

Well, it turned out that the oil filter adapter had worked
loose and was chewing up the threads in the accessory
case - that's where the metal came from. Problem is
so common, there's an AD on it. Gee, it sure was a good
decision to add that oil filter. Look at all the fun it gave
him.

One of the local FTU's 172 was taking off, a couple
years back. Lost all oil pressure. Turned back to airport,
landed. Turned out the oil filter adapter had cracked
and all the oil drained out of the engine. Gee, it sure was
a good decision to add that oil filter.

I really hate oil filters. More expensive stuff to break and
cause catastrophic failure. What everyone needs.

[iflyforpie]

That's good info on the relief valve... I wouldn't have believed that it would have been enough to reduce oil pressure to zero. That being said, it's a good idea to know where your oil pressure needle sits because any change might be an early sign of failure. For most problems, it is better to go from cheap to expensive (well, better for the customer anyways). An oil pressure relief valve is all of 15 min to pull... probably 5 min on a Lycoming.

As for the filter vs screen thing... it's debatable. On Lycoming... yeah, screens are better because of the filter adapter AD and the way they've made the screen housing. But on Continental... those brass screens have to be screwed in and out which have the potential to make even more metal. I've got an oil filter adapter on the IO-520 on my 206 and it just screws into the existing screen housing, and it makes access super easy and there is no mess.

[comfail]

I just bought a runout O-300 that has 3000 hours since factory reman, 1900 hours since MOH, and it just had the original oil screen setup. Crank still measures new limits and no other part in there showed anything but normal wear. My current engine has an STC'd filter adapter and its a leaky POS that looks like it is a fairly major point of potential failure. I've heard that if an internal failure such as a piston pin plug comes apart the oil filter will save you lots of grief, so that's why I've put up with the filter on my current set-up. Not sure what I should do...

[Colonel Sanders]

Cost/benefit analysis. Where I live, there is no airborne
dust. I don't live in the american southwest desert, with
the roadrunner zipping about, being chased by the coyote.

For me, an oil filter causes more problems than it solves.

[photofly]

What about those carbon flakes that the oil filter catches but the oil screen doesn't. Couldn't they clog the oil galleries etc?

[Colonel Sanders]

Lead deposits worry me more.

Next time you pull your prop, look inside your
crankshaft. You will be amazed what you will
find. Get a popsicle stick and carefully clean
it out.

[Heliian]

The advantages of an external full flow oil filtre far outweigh the disadvantages, how often do you want to change your oil? If it's leaking then that's an installation problem.

On Lycoming... yeah, screens are better because of the filter adapter AD and the way they've made the screen housing. But on Continental... those brass screens have to be screwed in and out which have the potential to make even more metal.

Most engines will have complied with the terminating action of that AD ages ago. The lyc still has a brass suction screen in the sump too.

[Taiser]

Hmmmmm... this post is food for thought.

I put a Lycoming O-235 in my homebuilt and was just planning on changing the oil screen setup for an oil filter adapter. I wasn't concerned over the fewer oil changes (the more the merrier IMHO) but thought the filter would catch way more junk than the screen would. Now maybe it's not worth it?? Not much dust around here either, but I will be flying from a grass field. Might have to rethink this and save $700.00!

[Old Dog Flying]

About 10 years ago I installed an ADC oil filter in my Grumman AA1A with the Lycoming 0-235 C2C and it has been a very good investment. Unfortunately the company that held the STC is no longer in business.

Barney

[Colonel Sanders]

Send me the $700 and we both win:

I get the cash, and you get a more reliable airplane.

[photofly]

I'll do it it for $400.

[Taiser]

About 10 years ago I installed an ADC oil filter in my Grumman AA1A with the Lycoming 0-235 C2C and it has been a very good investment. Unfortunately the company that held the STC is no longer in business.

Barney

Not too worried about an STC on my ship. Since it's a homebuilt I can put pretty much anything I want that I can get to fit. I was looking a fire wall set up but with all the gear I have on my firewall now it would be tight. I was planning on installing this...

http://www.aircraftspruce.ca/catalog/ep ... kkey=17907

About half the price as the firewall mount I was looking at but after hearing what the colonel is saying and the low hours I'll probably be flying this bird I might not bother and just go for the shorter oil change intervals...

[Colonel Sanders]

I remember I bought an airplane once with an
aftermarket airwolf (?) filter on it, with the
adapter and hoses and firewall-mounted filter.

Threw all that garbage in the trash and replaced
it with a stock pressure screen housing.

Private aircraft engines have a problem with
internal corrosion from a lack of use. Address
that problem.

[Taiser]

Well my engine is from a 1949 Piper! Seems to have lasted this long without too many issues (aside from the regular overhauls and such) in that time. Maybe I'll hang on to the screen!

[GA MX Trainer Dude]

It seems to me that Colonel Sanders has more of an issue with his experiences of oil filter failures so has adopted the attitude that they are an evil item and are unnecessary. He uses a Sport Aviation Article as reference to his view.

I took the trouble to look up the Sport Aviation article he referenced in his first posting and I came away with a different conclusion. CS is of course entitled to his point of view – and likewise I am entitled to my point of view. Having read Mike Buschs' many columns I don't think he would share the Colonels' point of view that the best thing for aviation engines would be to remove the oil filters. But you can decide for yourself.

Link to referenced article http://www.sportaviationonline.org/spor ... _2013#pg28

Well, it turned out that the oil filter adapter had worked
loose and was chewing up the threads in the accessory
case - that's where the metal came from. Problem is
so common, there's an AD on it. Gee, it sure was a good
decision to add that oil filter. Look at all the fun it gave
him.

So the first thing overlooked by CS about this is that the engine was certified with the oil filter system. There wasn't a choice regarding disposing of it!! Yes there is an AD on it - and it isn't rocket science to conform with the requirements.

The conclusion that I came away with was that human error in installing the adapter to the engine incorrectly was the direct reason there was aluminum contamination of the oil in the first place.

The second failure as I read it was the mechanic not performing a normal troubleshooting sequence for no oil pressure – for whatever reason. Once he was directed to inspect the relief valve he found the bit of metal holding the valve open and by all accounts the reason for the oil pressure problem that was caused by the effect of the installation error.

So on aircraft being operated without a normal CofA - and if you can do what you want regarding oil filters - then I guess if you are so inept as to being incapable of actually installing correctly a simple oil filter then maybe it is best that you remove this pesky bit of kit.

And yes it happens!! http://www.eaa.org/lightplaneworld/arti ... tex912.asp


On the other aircraft – like the one reference in the article – we don't have a choice – if it is a requirement of the engine to have a filter then we have to maintain said filter. If the engine was produced with only a screen for the oil system – then you don't have to have a filter – if the engine has an STC to install a supplemental oil filter as well as the screen – then you have a choice to use it or remove the package and rescind the STC on your aircraft.

But don't blame the oil filter system for the ineptitude of the dude doing the maintenance!!


Here is a link to oil filters etc. by Mike Busch - its a pretty good read.

http://www.sportaviationonline.org/spor ... pg=92#pg92

As for me - with 40 plus years in the business I have seen more than once where the oil filter has done what it is supposed to. I have done thousands of oil filter changes and have never had one fail or leak on me to date (seen others have issues and am not so smug that I don't think it couldn't happen to me tomorrow). I have had more than my share of having to remove over tightened filters installed by some ham fisted gorilla!!! Sometimes so tight the only way to get it off is to use a cold chisel and a big hammer.

I believe it was Kipling that wrote " Blame the man, not the material"


Mx

[Old Dog Flying]

My poor wee 0235 C2C came with a screen that would only stops pieces with a serial number on them and thus the ADC filter with a 20 micon screen that is very easy to inspect for shrapnel. And it proved to be a very good investment last spring.

I still do 25 hour oil changes and as the time was close I decided to do the deed and what I found was scary. The ADC showed a lot of aluminum as did the filter in my big funnel when I opened the sump. It turned out that No.1 cylinder had a 2 inch gouge in the wall and it was shaving the piston pin plug down with each stroke and the pin itself was next in line which would have caused a massive failure and forced landing.

The gouge was so deep that it could not be honed out or ground out leaving the jug unserviceable. I located a very low time assembly for a very good price, had it certified by me engine shop and installed the thing.

Had it not been for the efficiency of the ADC filter the resulting situation could have been deadly. I started my AME training in 1950, started flying in 1952, managed 4 FTUs and played with these toys all my life so CS you can read what you like into magazine articles but I'll stick with proven practices.

Barney