Skip to main content ↑ ↓
Topic: K&N air filter (Read 1318 times) previous topic - next topic

K&N air filter

My 1995 U320 with Cummins M11 came with a K&N air filter installed. Is it worth keeping or should I go back to stock air filtration.
1995 U320C SE 40'
Jeep 4x4 Commander - Limited - Hemi
"The Pack"  Yogi and Diesel our Airedales -  Charlie our Boxer/Akita mix. Gone but NEVER forgotten Jake our yellow Lab.
NRA Law Enforcement Firearms instructor - Handgun/shotgun
Regional Firearms instructor for national Armored Transp. Co.

Re: K&N air filter

Reply #1 –
Iframke, I liked the K&N on our last coach. It only cost me around $30 to have it serviced at a Ford garage in Cascade, ID. I delivered it to him in a garbage bag. They are also supposed to have long intervals between service.
Dick, '03 U320 40' Tag, 2 slides, Coach #6075
Full Timers
2009 Honda CR-V

Re: K&N air filter

Reply #2 –
The good thing about the K&N air filter is they never get stopped up with dirt.
The bad thing about the K&N air filter is they do not trap small grit, sand and dust, they just catch leaves and large things.
How would I know ? Simple answer, they never get stopped up where the paper gets stopped up. So you can put your head in a bag and drive on cheerfully until you need an engine job, it will not take long.  Can provide more info if not convinced.

Re: K&N air filter

Reply #3 –
Quote from: Dave M –
The good thing about the K&N air filter is they never get stopped up with dirt.
The bad thing about the K&N air filter is they do not trap small grit, sand and dust,

Our experience with K&N air filters was also not good.  One was installed as part of a Banks system in our class C (Ford V10), and caused repeated problems with the idle air control module, which we had to replace and the next owner also had to replace.  The IAC repeatedly fouled with oil and dirt and would cause the coach to stall at the most inopportune times.

After the fact research showed this was a common complaint for V10 owners.  It turned us off to K&N.

Michelle
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: K&N air filter

Reply #4 –
I am not aware of any engine manufacturer who approves of the K&N or similar filters.  Even the engine manufacturers with "no skin in the game"-- those who don't even make air filters like Caterpillar.

Brett
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: K&N air filter

Reply #5 –
Where is a good place to buy a replacement filter?
The selected media item is not currently available.Kent Speers
Locust Grove, OK
1993 U300 SSE 40' (Restored at FOT 2009) Build 4323
720 watts Solar
6V92TA DDEC Silver Engine
2014 Subaru Outback

Re: K&N air filter

Reply #7 –
Yes, Filter Barn, We purchase a lot of filters and now purchase bulk from Filter Barn, with their price and the biggie is the free freight on $100.00 orders, for us, the free freight is the winner in overall cost.  We buy direct from Fleetguard and price per filter is less, but unless we are at the wharehouse, the freight kills the cost of filters. 
So yes F-B works for us, we have certain requirements, they seem happy to work with us. Like Fleetguard only, no Fram etc.
FWIW

Re: K&N air filter

Reply #8 –
No K&N for me.  All the dirt track guys around here quit using them cause they were destroying race car engines.
1994 U225
build #4514

Re: K&N air filter

Reply #9 –
I always heard that the K&N filters were all hype, I would never buy one myself. I just thought I would ask before I toss it.

I guess they are on the same playing field as Monster Cable audio video products.

Thanks for the input.
1995 U320C SE 40'
Jeep 4x4 Commander - Limited - Hemi
"The Pack"  Yogi and Diesel our Airedales -  Charlie our Boxer/Akita mix. Gone but NEVER forgotten Jake our yellow Lab.
NRA Law Enforcement Firearms instructor - Handgun/shotgun
Regional Firearms instructor for national Armored Transp. Co.

Re: K&N air filter

Reply #10 –
Quote from: Steve & Michelle –
Quote from: Kent Speers –
Where is a good place to buy a replacement filter?

Oil Filters | Discount filters | Products | Diesel Engine Filters has been recommended before.

-M



THANKS!!! That's the one. I just couldn't remember the name. It is now bookmarked.
The selected media item is not currently available.Kent Speers
Locust Grove, OK
1993 U300 SSE 40' (Restored at FOT 2009) Build 4323
720 watts Solar
6V92TA DDEC Silver Engine
2014 Subaru Outback

Re: K&N air filter

Reply #11 –
I have no personal experience using K&N filters but had heard a lot of negative opinions. Here is just one of many on a BMW forum.

• First, conclusive tests from independent labs show that K&N filters, no matter how well-oiled and cleaned, let through huge amounts of large particulate that damages engines. Oil analysis shows 5x as much silicate contamination. Additionally, the oil from these filters tends to muck up the MAF and cause an engine-damaging lean-run condition.
• Second, an open element filter like that sucks in hot underhood air and subjects the filter to "fan wash", the swirl that creates a vacuum effect. On the E36 M3, we measure a 15hp loss from open cone filters.
• Third, the E34 airbox is designed with an integral velocity-stack style venturi at the opening. Running one of these engines on a dyno, you can cause a 5hp drop just from putting your finger on the stack lip. Removing that airbox undoes a lot of good BMW engineering. Yes, these filters make a "really cool" noise... but noise does not equal power. Stick with a stock paper element in the factory airbox, you're not getting any more power with a K&N garbage-filter, just damaging your motor."


For $31, we can buy a new stock paper air cleaner element that was designed with our U300 in mind. With the engine in the rear, it will pick up much more dirt than a front engine machine, especially if you go down dirt/gravel roads. Why take a chance?
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: K&N air filter

Reply #12 –
The most funny K&N filter disaster I have came across was a Med Doc who purchased a old GM 4101 bus converted into a nice comfy RV, he had it converted from the 6-71 4 speed to a 8V-71 auto, after the conversion I talked him into parting with the old oil bath air filter setup, as it was about 99% stopped up, removed all that mess and installed a nice proper paper cartridge setup very close to what is on the ISM series 320 coach's.

Six months later he is back needing work on the DDC 8V-71.  Found the paper filter gone with a K&N in place. I asked why, Answer was the paper gets stopped  up too quick and the K&N never gets stopped up.  Yup the engine was way down on compression and a lot of blow by even for a poor 71 series. No amount of discussion allowed him to get it.

Hope he was a good Doc as his mechanical skills were never developed I guess. 
How I got educated on the K&N stuff.  ;D
 

Re: K&N air filter

Reply #13 –
Quote from: Dave M –
The most funny K&N filter disaster I have came across was a Med Doc who purchased a old GM 4101 bus converted into a nice comfy RV, he had it converted from the 6-71 4 speed to a 8V-71 auto, after the conversion I talked him into parting with the old oil bath air filter setup, as it was about 99% stopped up, removed all that mess and installed a nice proper paper cartridge setup very close to what is on the ISM series 320 coach's.

Six months later he is back needing work on the DDC 8V-71.  Found the paper filter gone with a K&N in place. I asked why, Answer was the paper gets stopped  up too quick and the K&N never gets stopped up.  Yup the engine was way down on compression and a lot of blow by even for a poor 71 series. No amount of discussion allowed him to get it.

Hope he was a good Doc as his mechanical skills were never developed I guess. 
How I got educated on the K&N stuff.  ;D

Experience is your best teacher.  It just ain't one of the cheap ones!.....original quote from 'Spike'

On other MH forums I spent a lot of time explaining why the K&N plus other similar are very bad for engine life.  If these 'filters' were anything to consider, major on-highway truck fleets would be using them as air cleaner maintenance at one per year times 30,000 plus trucks for some fleets is major maintenance expense!  K&N and the others do provide more air flow in a given package size.  That is all they can do.  In a diesel engine, more air flow is not required with stock fuel delivery mapping from the ECM.  Diesel engines already have more air for combustion than required.  Reducing inlet restriction is pointless in that process.  Then there  are those who are not satisfied with the stock horsepower but must change the chip to increase fuel delivery and alter injection timing.  For them, the K&N does supply the additional needed air flow.  Along with that increased air flow comes the dirt that conventional air cleaners remove.

I always thought that the point was to get out and travel and see the sights.....not the inside of a repair shop!

Gary
Gary Spires
Coolants, Cooling Systems, Filtration, Diesel Engines