Stop changing air filters, your killing your engines!

[Brian in Oregon]

Yes your right, large machines have cyclonic pre cleaners that dump 99% of the dust before it gets to the filter, but you've missed the point a bit.

You will be doing your engine a favour if you changed your air filter only when it is creating a restriction (regardless of what application the engine is in). A dirty filter is doing a better job of filtering the air. Simple as that.

The way I see it, when an air filter starts getting dirty, the larger pathways through the filter media do not become as easily clogged as the smaller pathways. The larger pathways continue to flow and pass small and larger particulates. The smaller holes clog up first, probably due to larger particulates getting stuck and then getting sealed with smaller particulates. So, does the air filter become more effective at filtering? I say no, it just puts more load through the larger passages, and these do nothing for filtering the smaller particulates.

I'd still like to hear from Donaldson that what they state applies to small passenger vehicle engines.

 

[DPHFJ40]

Diesel engine manufacturers specify a minimum dirt holding capacity and minimum particulate size for air filters used with their engines. The engine manufacturers must approve the OE's installation before they will warranty the engine so a new OE filter element will filter out the larger particles that will effect engine lifle. A previous post gave most of the reasons Donaldson doesn't want the filter over serviced. One of the other reasons is dust on the dirty filter element falling into the open housing or intake piping. It's not always possible to mount the air cleaner housing where it's easy to change the filter so large particles that were caught by the element could fall into the housing while removing the element. Diesel air cleaner elements can be 3' long and weight 20 lbs so there's a big difference on how carefully you can remove one of these.

 

[PabloCruise]

I'll take the anal filter guy anytime.

They make anal filters?

Quality!!!

 

[Coolerman]

OK here is a site that did some real world testing of some different filters: K&N, Amsoil, stock paper and a couple of racing filters. VERY interesting reading. Read it all, including the related links, before coming to conclusions. Air Filtration Test

 

[Coolerman]

but then, I never over-oiled the element either. .

Nor did I. I took it out way before it was due. Read the site above. It has many references to the issue here.

I'm having a good time imagining your duct tape mods.

I wonder how many other things on the cars were affected by the ash? I would guess that most seals would take a beating from the abrasivness of the glass ash?

 

[Trollhole]

OK here is a site that did some real world testing of some different filters: K&N, Amsoil, stock paper and a couple of racing filters. VERY interesting reading. Read it all, including the related links, before coming to conclusions. Air Filtration Test

I'm not buying it. It wasn't controlled. Rain, wind, time of year all play an important role. Very cool study though.

 

[Coolerman]

Agreed it wasn't a controlled study (he also admits this), but it would be more like what Joe Blow would encounter on the street. The whole point of it was to provide at least some real data instead of internet gossip.

 

[lostmarbles]

OK here is a site that did some real world testing of some different filters: K&N, Amsoil, stock paper and a couple of racing filters. VERY interesting reading. Read it all, including the related links, before coming to conclusions. Air Filtration Test

Thanks Coolerman. I buy what he says. (I'd been waiting to find an article like that by someone I find "credible".)

I'll probably be running my 2-stage foam filter on my BJ40 till it gets dirty, fit the spare one and do the same, ..... and then go back to using standard paper filters (having thrown away all my foam filters and not bothering to wash/re-oil/reuse them).

I was sucked in by "superior filtration" claims relating to oiled-foam filters (but at least I didn't go for the gauze/cloth K&N-type). But I did buy spares for the main filter and pre-filter and extra oil.

Never mind - At least I can use the oil and detergent on my motorbike air filters. (No wonder my motorbike engines wear out so fast! Their filters are all oiled-gauze or oiled foam.)

Just another few hundred dollars "thrown down the gurgler" from another poor decision of mine! What the heck!

 

[beejay42]

Well, this has been a good read- Thanks BEE-JAY42 -and will result in me not changing my Donaldson filter yet as I was planning to do. It's one of the centrifugal ones, and though it looks a little dirty it seems there is a lot of life left in it yet- and thus some of its best life
Probably the single best thing I did for my engines air was to replace a cracked air hose that LED to the filter I can't believe the PO didn't do it??? Seemed more interested in getting the stickers on the side windows lined up perfectly and mirroring each side

 

[lostmarbles]

This is confusing - I've just realised there are TWO people here with almost exactly the same usernames. (beejay42 and BEE-JAY42) And both from Oz!

There must be the makings of a dispute over ownership here!

 

[beejay42]

This is confusing

well we do call you lostmarbles don't we

I've just realised there are TWO people here with almost exactly the same usernames. (beejay42 and BEE-JAY42) And both from Oz!

There must be the makings of a dispute over ownership here!

Yeah, when I first read it I was like- I can't remember posting that thread... hang on, I don't even know what I'm talking about

Oh well, for those of us that choose such original user-names such as mine, we must accept the chance of multiplicity.

If in doubt, I am the one who doesn't know what he is talking about, asks noob questions, and posts photo journals of every cup of tea he makes

 

[haystax]

This is confusing - I've just realised there are TWO people here with almost exactly the same usernames. (beejay42 and BEE-JAY42) And both from Oz!

There must be the makings of a dispute over ownership here!

Huh Huh Beavis, he said "B" "J" huh huh...

 

[cruiser88]

Oh my.

 

[Hobbs]

I had the good fortune of attending a short course run by Donaldson air filters at work the other day. It open my eyes to a few new facts that I thought I would pass on.

* A clean air filter doesn't catch dirt, it takes time for the holes in the filter media to become blocked by larger pieces of dust. I was aware there was a run in period but didn't realize it was so big, a large machine working under the most extreme conditions in a coal mine will take over 100 Hours before it's filters are blocked enough to become effective.

* Stop changing filters, If a piece of equipment working in a coal mine takes 100 hours to prime it's filters so I can only guess how long a car would take. Don't change based on time or distance traveled, install a restriction indicator and change when the indicator show a large enough restriction.

* Power loss due to blocked filters is a little bit of an urban legend..... So basically any power increase noticed after changing a filter is probably in your head.

* Don't tap filters (even gently) to clean them, this can crack the sealant between the paper element and the filter end caps. Clean only with LOW pressure air, remember you don't want to dislodge the dust that is blocking the large holes. Also remember that the filter isn't as dirty as you think it is.

* A large engine (that being 40 litres capacity and up) will only require to draw half a cup (125 Grams)of dust through it's entire life before it is "dusted" and will require replacement, So I can only guess at how much a car engine could tolerate.

Hope I have helped save people a few bucks, both on air filters and engines.

I have been watching/reading this thread with great interest. I have been very hesitant to post up due to the conflict already witnessed. I have worked in the automotive/equipment repair industry for 23+ years and have seen a wide variety of equipment and vehicle applications and operating situations.

I mean no disrespect to anyone, especially Bee-Jay42, who brought some very thought-provoking info to our board. After reading this thread numerous times, these are my thoughts on air filter maintenance/replacement:

QUOTE- "...a large machine working under the most extreme conditions in a coal mine will take over 100 Hours before it's filters are blocked enough to become effective."

If this is true, should we assume that less extreme conditions will result in a longer time interval before an air filter becomes effective? Hmmm. My Land Cruiser, at 60 m.p.h. (on a good day) would take 6,000 hours in a coal mine before the air filter first BECOMES effective. Is my filter doing little or nothing before this threshhold?? If so, I would expect to see a pile of low mileage junk F, F2, F3, and newer engines for sale here on 'Mud and in the local junk yards. Toyota didn't go big by producing junk for markets world-wide.

QUOTE- "Don't change based on time or distance traveled, install a restriction indicator and change when the indicator show a large enough restriction."

The Toyota Factory Service Manual (pictured below) recommends Inspection and Replacement based on mileage and time, and modifies these parameters based on adverse operating conditions. Toyota chose not to install restriction indicators and still does not install these devices on production consumer vehicles (to my knowlege). I like my F.S.M.

QUOTE- "Power loss due to blocked filters is a little bit of an urban legend..... So basically any power increase noticed after changing a filter is probably in your head."

Inversely, I work with a crew of experienced operators who can recognize a slight power loss. Sounds unlikely, but this is a real-world situation which I have seen with regular frequency. An operator who works a michine 8 hours a day for years probably knows the machine better than most....

QUOTE- "A large engine (that being 40 litres capacity and up) will only require to draw half a cup (125 Grams)of dust through it's entire life before it is "dusted" and will require replacement, so I can only guess at how much a car engine could tolerate."

How much dust can a car engine tolerate if a large engine will only tolerate 125 grams of dust through it's entire life before it is 'dusted'?' Red Herring?? How do we compute the 'dust quotient' for a small engine? Grams per liters? Cylinder bore area and bearing surface area? Help me out, here. I do not see a huge departure between large and small engine air filtration systems theory other than the fact that 'some' large equipment do run in very adverse conditions some (most) of the time.

I have a hard time buying some of these arguments.....

 

[Brian in Oregon]

Nor did I. I took it out way before it was due. Read the site above. It has many references to the issue here.

I'm having a good time imagining your duct tape mods.

I wonder how many other things on the cars were affected by the ash? I would guess that most seals would take a beating from the abrasivness of the glass ash?

Actually, few vehicles had seal damage, excepting some which were inundated with ash. overall we were pretty lucky. And yeah, the duct tape all over the air cleaner looked pretty redneck. Larry the Cable Guy would have approved.

 

[lostmarbles]

As far as the claims made by "the Donaldson rep" are concerned - I "take them with a grain of salt".

I imagine most people at an "Air Filtration Seminar" (or whatever it was) would have already heard all there is normally to be said about air filters and would get bored hearing it all again. So I reckon this person wanted to "shock people to attention" by challenging their "common sense (traditional) beliefs".

You gotta admit - There would have been a lot of discussion following his "presentation" (just like there is here). And I'll bet they have cunningly worked out that that translates into "Sales".


(My 2C worth)

 

[Coolerman]

One last thing: I am driving a Saturn with a 4 banger I bought from my sister. It has 268,000 miles. Had 265,000 when I bought it. I don't think she changed the filter very often. It still runs great and gets 25 MPG. Paper filters must do something right...