K & N Air filters

Bobdown · Guru

K & N Air filters

Paul · Veteran Member

When I had my injectors bench tested I was told the K&N filters were probably not the best idea for my lifestyle as they can produce a slight film of the oil that is used on them to effect the MAF sensors which could lead to more regular cleaning needed. He mentioned that they were an asset on machines that only operate for shorter periods of time. I cleaned my sensor and went back to paper elements and have noticed a reasonable difference, I'll wait and see how things go, cheers.

blaze · Guru

free flow filters mean less filtration, more sand in your engine. the best filter is a blocked one but not good for power/economy, so a clean paper one is best
cheers
blaze

swamp · Senior Member

HI
Oiled filters should be serviced a lot . Why the oil dries and the oil migrates downwards. They are great for black top road racing .
If u are worried about a paper element just change it every 20,000km or when dirty whatevers first or even when the service schedule says to . A paper element that's dirty filters better because all the largest pores are blocked. Of course if u leave a filter to long it restricts air to the engine .

To gain serious power from an intake system it needs to be poorly designed . Most modern systems are not . In saying that sure u will gain some power if all pipes and fittings were alot larger with cold air induction . The cost would be high for small gains thou.

If u chip an engine , upgrade exhaust ,larger intercooler , block egr , catch can ,cold air intake . Once all this is done u will see a benefit . The engine should demand more air. At this stage a K&n filter would be beneficial .
Did I say u might need pistons and clutch as well .

Everything works as a package the air filter is only 1 piece of a big picture .

Whenarewethere · Guru

I just replace the filter more often. Also cabin air filter, that get pretty bad.

My first car had an oil air filter & it was recommended to clean it every 5000km. I cleaned it a few times & there was a lot of crap in the oil.

I would stick with the manufacturer's recommended filter, they are not that expensive. A lot cheaper than buggering up today's complex engines.

T1 Terry · Guru

We used the foam oiled type air filters on the rally cars because they worked so much better than the paper elements. You do need the sock over the top of the main filter for proper filtration, the sock collects the dirt first, is easy to peel off and check the surface condition of the main filter. If it is still clean, fit a cleaned and oil sock over the main filter and service the socks when you have a bit of free time.
The talk about oiled filters V paper filters is a bit twisted, new paper filters are oiled as well. The paper can only work if it has holes in it, that means any dirt smaller than the holes will pass through. Bang the filter and blow it out does seem the remove a lot of dirt, but it also makes bigger holes.
To see how well your filter will work, hold it up to the sun and look from the inside through the paper. You might be shocked by the number of tears or holes you detect doing this, but you might also find you can't see through it at all. If you can't see through it, all the holes are blocked.
Oiled foam on the other hand relies on the sticky oil holding onto the dust and the more dust that builds up the more work you can see that it has done. You do need to use the special oil though, it is a blend of oil intended to be very strong in its bonds to other molecules of the same oil so it won't pass through the foam readily, some will and that keeps the main filter well oiled.
As far as the K&N filters, not a big fan, their oil isn't near as sticky as the Finer Filter oil and I'm not sure if it can be used on the K&N filters because they are cotton sheet based.
All of this is based on when I had my workshop 20 yrs ago, so it might be a bit dated, Finer Filter might not even exist any more.

T1 Terry

Jaahn · Guru

Hi smile

I agree that any oiled filter only works by the dirt sticking to the 'oil.' The foam or whatever just changes the air direction multiple times to make it meet the oil so the dirt sticks. So if you use one in dirty condition clean the sticky dirty oily thing regularly. Other wise just use paper filters and carry a spare good brand. Probably true that the oil might carry over to your MAF sensor. aww

A while back my mate bought a farm and I helped service some of the machinery. The old diesel tractor was going OK but obviously had not been properly serviced for years. Those oil bath filters have a metal mesh and a bowl full of engine oil that the air flow carries up into the mesh to wet it. When the engine stops the oil and dirt drops down into the bowl and the dirt settles. Then next start the oil goes up again etc. This filter unit had solid dirt in the bowl to the top level. Oily packed solid like cement. The mesh was completely full of grass. We wondered why it actually ran !! In the end we had to get the pressure washer into both the mesh and the bowl to get them anyways clean ?? The tractor seemed to run just the same after hmm The grass must have filtered the air OK because the engine runs well after 60 years ploughing and slashing !

Warren-Pat_01 · Guru

G'day Bob,
I was tempted to go to a K&N filter at one stage when I had our GQ Patrol. I was using Finerfilter-Unifilter elements but I found what I was using had better filtration than the K&N with less risk of oil going where it shouldn't.

I've only used paper filters on the GU

Whenarewethere · Guru

Jaahn wrote:
Those oil bath filters have a metal mesh and a bowl full of engine oil.....
.....engine runs well after 60 years ploughing and slashing !

That's what my car had, but it also had cylinder liners so everything was a bit more bullet proof. 260k km & the engine was perfectly ok.

Jaahn · Guru

Hi smile

Another point to make is the filter design. I am not knowledgeable about the new current 4WDs style of air filters. But in the past diesels had a centrifuge round filter in a cannister that had the air coming in at a tangent and a vane deflecter to spin the air to drop the dirt into the bottom of the cannister body. The bottom cover was removable to get the dirt out. This system will remove most of the dirt and dust before it gets to the paper filter and is the usual type of filter fitted to all trucks. aww The old oil bath filters did that too.

I notice that this style has been changed to flat style filters that have no effort to spin out the dirt, as far as I can see. More profit for the dealers. On another note the manufacturers do use some R&D to determine a good place to pickup the intake air from a dead point that may be cleaner. I wonder whether the aftermarket suppliers of snorkels spend any time on that function or just on the sexy appearance. hmm

Jaahn

Whenarewethere · Guru

Intaking air from a dead area in the engine bay is what my first car did, also a centrifugal air flow & up through the oil.

There was never much dust in the engine bay as there were a lot of surfaces that the dust would hit before the air actually got to the intake.

I have always thought the air snorkels are probably putting more dust into the system than they are trying so solve.

Maybe good for deep water but I but there are not too many who have raised breather tubes on transmission etc.

swamp · Senior Member

Hi
It depends on where/ application u use the filter .
Agreed an oil bath filter works best.
Running a foam filter wet with oil in a machine . Oil migrated to bottom of filter causing a non filter condition . My oiled filter would be cut /sliced by the filters internal wire cage. In saying all that in very very dusty condition s when first installed it would clean far better than any paper element . The oil would change colour . No dirty residue ontop of carby anymore . This machine had a Donaldson further up stream as well !!

T1 Terry · Guru

Oil migrated to bottom of filter causing a non filter condition
Yes, a common issue when not using the correct oil, Finer Filter actually call it Fluid to differentiate it from normal oil. The other common mistake is washing the foam in petrol rather than turps, the foam degenerates rapidly when washed out in petrol.

T1 Terry

Aus-Kiwi · Guru

They are fitted as std in Explorer . If your in dusty conditions? They have a foam sock the covers element . Paper type have that option also . My old work Rodeo was fitted with paper and foam for extreme conditions. Where air enters helps a lot with dust and water . Over oiling or wrong oil can put air meter calibration out . Just spray hot wire with carb or brake cleaner .

Bobdown · Guru

Video of K & N filter being cleaned and re-oiled...............Bob

www.youtube.com/watch

rockylizard · Guru

Gday...

This video shows that changing the air filter in my Landy takes about 3 mins - and 2min20secs of that is removing and replacing the cover.

I just do it every 10,000Km - six monthly.

https://www.youtube.com/watch?v=Fb9oDC3bebY

Why would I change to a K&N filter? Takes more than an hour to remove, clean and replace the K&N filter. hmm

Just where is the advantage?

Jest sayin' hmm

Cheers - John

Aus-Kiwi · Guru

Ahh we dont generally have stock paper filters at home . If you cant take filter out and clean in 10 minutes ? Your not doing it right or taking your time .

Whenarewethere · Guru

I have a spare air filter $38.50 Inc GST with a Land Rover sticker on it.

If I need to save a few dollars on an air filter I should have bought a bike instead.

Whenarewethere · Guru

As best as I can tell the paper filter I have has twice as many pleats so probably twice the surface area.

I very much doubt the paper air filter's air flow is twice as restrictive.

Apart from the waste of one's life cleaning the K&N filter just the waste generated with all those aerosol cans & oil & water on the ground from cleaning. My neighbours would not be impressed to say the least.

Aus-Kiwi · Guru

Oh the dramah !! Doesnt matter just service the vehicle !! Crunch or fold ?

Peter_n_Margaret · Guru

I have been using washable oiled foam filters on the OKA for 15 years.

I also have a very open oiled foam element at the entry to the snorkel. That helps to indicate the level of dust being experienced and is a guide to when the main filter should be checked.
The main filter is 2 layers of foam. Virtually zero dust gets to the second layer. When the outer layer gets too dirty it is an easy matter to wash it in turps and re-oil it (I actually use hydraulic oil as it is light and I carry some anyhow). The outer foam layers last about 4 years and I make my own replacements.

When I first considered using this, it was suggested that the resistance would be too high, so I installed a vacuum gauge and compared the readings with the published limits for the Perkins motor. It has never been a problem, but does give another guide to the build up of dirt in the filter.

Apart from being very convenient, it has probably saved us a fortune over the years.
Cheers,
Peter

Radar · Guru

Up until we brought our 2014 model car our workshop encouraged us to use K&N for near on 30 years but the problem is with these more high tec motors with sensors and computer the most smallest amount of oil plays havoc with computer settings.

So we use a standard air filter and change it every 10 thousand kilometers when the car gets serviced.

T1 Terry · Guru

Whenarewethere wrote:
As best as I can tell the paper filter I have has twice as many pleats so probably twice the surface area.
I very much doubt the paper air filter's air flow is twice as restrictive.
Apart from the waste of one's life cleaning the K&N filter just the waste generated with all those aerosol cans & oil & water on the ground from cleaning. My neighbours would not be impressed to say the least.

You have an ice cream container and a bottle of turps. Pour the turps into the ice cream container, wash the filter in the turps and hang it above the ice cream container to let the excess drain off. Let the dirt settle to the bottom, pour the turps back into the bottle while being careful not to pour the dirt off the bottom of the container. Discard the last bit of turps and dirt on a weed you've been trying to kill. wipe the container out and pour in the sticky oil, enough the cover the bottom of the container. When the turps has evaporated off the filter foam, drop it in the oil and fold it over a few times, take it out and place any that isn't oil soaked into the remaining oil in the container. Now fold the foam up small enough to fit in your hand, squeeze till the oil runs out between your fingers. Shake/scrap that off into the ice cream container, fold the filter a different way and repeat till next to no oil squeezes out, job done, place the filter in the plastic bag ready to be used next change. If you collect a few to have as spares you can do a bunch at the one time making the over all time spent on each filter fairly short. If you have a spare plastic bottle, pour the remained of the filter oil into that bottle so you can use it next time.

The next service, the dirt will have settled out of the turps into the bottom of the bottle and the oil should have separated out any discoloured stuff into the bottom of the plastic bottle. The service is a repeat of the instructions above.

Not water, aerosol cans or waste mess on the ground. If you are flush with money and don't mind spending the $$ on new filters on a regular basis, you shouldn't whinge about the cost of things because you are obviously well enough off not to need to save a few $$. But what about the waste going to land fill of all those thrown away paper filters? wink

T1 Terry

Peter_n_Margaret · Guru

What Terry said is pretty much what I do.
The bits and pieces to perform the cleaning and oiling would cost about $1 instead of $20 or $30 per time and if I did not do that I would need to carry at least one spare filter in the bush which is very bulky. In dusty conditions an air filter may be full of dirt in less than a week.
Cheers,
Peter

T1 Terry · Guru

Anyone who uses the oiled foam filters with a sock secondary cover will know just how quick they can end up coated in dirt. You just don't see it with a paper filter and some of the fine dust an oiled foam filter removes from the air will actually go straight through a paper filter, that fine talcum powder type dust. That is why the genuine part number paper air filter has an oiled paper element, so it can trap that very fine dust. Very few of the after market paper filters have the same ultra fine filtration.

T1 Terry

Aus-Kiwi · Guru

An extra filter or even oil bath before main filter if concerned . Or cyclic https://www.donaldson.com/content/dam/donaldson/engine-hydraulics-bulk/catalogs/Hydraulic/North-America/F112100-ENG/Hydraulic-Filtration-Product-Guide.pdf

Whenarewethere · Guru

T1 Terry wrote:
Whenarewethere wrote:
As best as I can tell the paper filter I have has twice as many pleats so probably twice the surface area.
I very much doubt the paper air filter's air flow is twice as restrictive.
Apart from the waste of one's life cleaning the K&N filter just the waste generated with all those aerosol cans & oil & water on the ground from cleaning. My neighbours would not be impressed to say the least.
You have an ice cream container and a bottle of turps. Pour the turps into the ice cream container, wash the filter in the turps and hang it above the ice cream container to let the excess drain off. Let the dirt settle to the bottom, pour the turps back into the bottle while being careful not to pour the dirt off the bottom of the container. Discard the last bit of turps and dirt on a weed you've been trying to kill. wipe the container out and pour in the sticky oil, enough the cover the bottom of the container. When the turps has evaporated off the filter foam, drop it in the oil and fold it over a few times, take it out and place any that isn't oil soaked into the remaining oil in the container. Now fold the foam up small enough to fit in your hand, squeeze till the oil runs out between your fingers. Shake/scrap that off into the ice cream container, fold the filter a different way and repeat till next to no oil squeezes out, job done, place the filter in the plastic bag ready to be used next change. If you collect a few to have as spares you can do a bunch at the one time making the over all time spent on each filter fairly short. If you have a spare plastic bottle, pour the remained of the filter oil into that bottle so you can use it next time.
The next service, the dirt will have settled out of the turps into the bottom of the bottle and the oil should have separated out any discoloured stuff into the bottom of the plastic bottle. The service is a repeat of the instructions above.
Not water, aerosol cans or waste mess on the ground. If you are flush with money and don't mind spending the $$ on new filters on a regular basis, you shouldn't whinge about the cost of things because you are obviously well enough off not to need to save a few $$. But what about the waste going to land fill of all those thrown away paper filters?

T1 Terry

Turps & spirit based paint or cleaning air filters, l need activated carbon face masks, gloves, safety glasses..... Couldn't be stuffed & I live in a unit where we are not allowed to store chemicals etc. Paper is less offensive than all the other stuff.

Aus-Kiwi · Guru

Who and were does the vehicle get serviced ? Sheesh !! Do we winge about old engine oil ?? Filters etc .

Whenarewethere · Guru

I think the old engine oil is burnt in the Sydney Harbour Ferries so we breath in all the exhaust to clean the air. Recycling at its best!

swamp · Senior Member

Hi Terry
Have cartons of the stuff in the workshop ,so yep unless I`m reading it wrong it says Finer Filter oil . Some applications DONOT suit oil bathed foam air cleaners .
There was 2 viscosities as well have both .

In dusty conditions have 2 filters and a spinner precleaner which ejects the coarse particles . This system works well .