K&N Air Filters??

[The Evil Twin]

I've always read it's a Bad idea to use K&N filters in diesel applications. They allow too many small particles through.
View attachment 234315

ANY engine.
I run BMC filters in the race bikes. Similar to KN filters. I can attest to the lack of filtration in the trade for flow.

 

[McE]

Tired of listening to YouTubers "talk" about what to run?? Want to find out for yourself??

Buy a pack of white cotton gloves. Buy whatever engine air filter you want to run. Remove the intake tubing to clean completely. Install new air filter. Drive for 5,000 miles. Remove the filter and intake tubing. Put on white cotton gloves. Wipe the inside of the tubing with your hand/fingers. Inspect white cotton glove to see what (if any dirt/grit/grime) has accumulated on the tubing inside.

My point : Sure some oil analysis is going to report what's IN the oil......but it hasn't proven WHERE it came from. Cause if silica has increased in an oil report, you BETTER be able to find it along the air path.

Now.....what happens when your "white cotton glove" inspection reveals NO accumulation of dirt/grit/grime??

Anyway.....it's way too early for all this. Back to coffee.......

If the only variable between oil samples is the air filter, there's your answer. It's going to take a lot more than 5k miles of accumulation to be able to see it on a glove. Most of the sub-10-micron particles are not sticking to the intake tract unless you over-oil the filter.

Filters like the K&N increase engine wear by being measurably less efficient than OEM style filters. That's objectively true. How long before it causes issues is another discussion. Some guys prefer the increased flow and don't mind the trade-off. Nothing wrong with that.

 

[knaffie]

K&N filters are terrible. They let too much dirt through. I've had first hand experience with this. Properly oiled and using a pre-filter and I saw the dust inside my intake. Never again. K&N's claims that you can increase mileage and horsepower just by replacing the air filter are (if ever true) not without compromise.

For all the effort the manufacturers are going through to maximize power and mileage, they're not going to overlook the air filter.

 

[Ceerix]

Properly oiled?
K&N Filter comes pre-oiled.

You only need to re-oil it when you cleaned it
"CLEAN ONCE EVERY 5 YEARS: Engine air filter only needs cleaning every 75,000 miles under normal highway driving conditions (based on the average miles driven per year of 15,000 miles) "

 

[knaffie]

Properly oiled?
K&N Filter comes pre-oiled.

You only need to re-oil it when you cleaned it
"CLEAN ONCE EVERY 5 YEARS: Engine air filter only needs cleaning every 75,000 miles under normal highway driving conditions (based on the average miles driven per year of 15,000 miles) "

Off-road use requires much shorter cleaning intervals than highway.

 

[Kzxer]

What is the consensus on K&N Air Filters for 6.7L diesel engine? Are they any good or should I just stick with a Fram or Motorcraft air filter? Thanks in advance!

Edited my original question to be clearer - looking for an engine air filter recommendation. Thanks!

Most people agree that K&N filters flow well, but the filtration isn’t as good as the OEM-style paper filters. For a 6.7L diesel, I’d stick with Motorcraft or another quality paper filter since they protect better against fine dust.

 

[AZsurveyor]

Off-road use requires much shorter cleaning intervals than highway.

Both my filters, cabin and air get inspected once a month mandatory. Replace as necessary.

The cabin, 95% of the time gets a new filter; the engine filter, running a dry element with a prefilter, I may extend it 2 or 3 uses with cleaning/washing the reusables per said intervals.

Fine dust after 4 weeks (~2,500 miles) of various dust, from various terrains across the state or Arizona.

Rig is used as a work truck.

 

[DTX2023Tremor]

Both my filters, cabin and air get inspected once a month mandatory. Replace as necessary.

The cabin, 95% of the time gets a new filter; the engine filter, running a dry element with a prefilter, I may extend it 2 or 3 uses with cleaning/washing the reusables per said intervals.

Fine dust after 4 weeks (~2,500 miles) of various dust, from various terrains across the state or Arizona.

Rig is used as a work truck.

View attachment 235487

I still have red Sedona dust in places. Not sure I'll ever get it all out without having to do a really deep detail inside and out!

 

[Fozzy]

This K&N pre-ran the Baja 1000 and was exposed to more silt than a lifetime for an average user. Gas motor and in a large aluminum air box. Motor rebuild only when needed, not every race or even every year. I think you would have to oil it incorrectly for years and run it for years before you had trouble just daily driving. But I like my warranty and is the small power or mileage bump even worth the hassle these days? I use to like the big filters on my diesels to try and get more turbo whistle. I would usually run one until I thought it was getting too dirty and just buy a new one. I have seen guys get build up on their compressor wheel with over oiling and high boost pressures.

Top

Bottom, intake side

 

[AZsurveyor]

I still have red Sedona dust in places. Not sure I'll ever get it all out without having to do a really deep detail inside and out!

Now you understand why I didn't go with the black interior ..... but rather "dust" color.

 

[modified]

I still have red Sedona dust in places. Not sure I'll ever get it all out without having to do a really deep detail inside and out!

My “new truck” smell is officially gone after last weekend. It's now that signature Big Bend dust scent.

 

[Optimus🤖]

My “new truck” smell is officially gone after last weekend. It's now that signature Big Bend dust scent.