It's not so much what it will do to the engine, but rather what it will do to the turbo.
Yes the engine will suffer too, but the turbo takes the hit.
That may be microscopic sized dust particles, but it is STILL abrasive materials.
Turbo spinning at 100,000 rpm will get sandblasted in a hurry being fed a mixture of sand and air.

 

...which also grinds on the rings ruining compression. Then it ends up in the oil where the smallest bits that don't get trapped in the filter wear on oiled parts. Not worth the risk IMNSHO....

 

That looks like a under oiled filter to me. My bro has a K&N cold air intake on his '99 for some time and with 116K and no signs of dusting...

I already bought the the filter and prefilter. If I start to see signs of dusting I will ditch it but highly doubt it.

 

Time to drag this one back up:
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Hey guys, I've got a 2002 7.3 I've had a performance chip for a while and wanted to get more performance. I was recommended to port and polish the intake and exhaust. We found out they used abrasive material to do it like gritty sand.

So I got with my friend that tunes Hondas and we decided to try it ourselves. We got a bag of sandblasting sand and hooked up into the intake and started the truck. We had to hold the accelerator so it would run. He wanted to let the engine suck in the sand through the intake so it would port it out and then push it out the exhaust so it would port the exhaust manifolds.

I was worried that it might cause problems but he figured it'd be OK as long as we didn't make boost and it get sucked in the turbo. After running the car and letting it suck in sand we got about half way through a 25 lb bag. The check engine light was on and the engine was bucking and kicking and sounding really weird. We stopped and hooked the truck back up normal and took off the sand supply.

We tried to start it again and it was really hard. Once started it couldn't idle and kept making weird noises. We took it out and drove it and it started to make scraping and knocking noises.

Help! Can anyone tell me what to do! My buddy only does Hondas so he doesn't know much about diesels.
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Pop

 

Sounds like an expensive "experiment".

 

Classic Pop, always makes me smile because I can just see some Fast and Furious dweeb with a wing on the back of a front wheel drive car thinking that sounds like a good idea.

OTOH, didn't Chevy actually use Bon Ami on the '55 265's to cure oil consumption when the rings didn't seat or is that an urban legend?

My grandad had a 55 coup that my parents bought from him in the late 60's and I remember my dad talking about the Chevrolet garage having done it.

 

I run a AFE big boost filter from Riffraff Diesel: AFE "Big Boost" BHAF Washable Filteron mine but I wouldn't put a K&N on it . I've run the k&n on all kinds of gas engines but not on diesels after all I have seen and heard here.

 

Supposedly there was a TSB issued, but I suspect it would be impossible to run across a copy to prove it ever actually existed.

In fact, they probably issued a "Destroy All Copies" order a few months later.

I sure would have if I were them.

Pop

 

Wasn't there Some kind of walnut shell mix Ford used to clean the intake valves by simply sucking it through the intake?? Non-turbo gassers obviously, but an interesting process nonetheless....

 

Here is an ASTM-based series of tests on aftermarket air filters, including K&N.
Air Filtration Test

This series of tests show that K&N has lower pressure drop, which means it flows more air than all the others, but at the same time it passes more dirt than all the others by a large margin.

Consider how a filter element can create more airflow...
1. more surface area with the same sizes of openings for the air to flow through.
2. "open"the element up (either larger or smaller) to allow more air to flow through the surface of the element (but remember, fine particle dust will also be allowed to pass through these larger openings.

Now, just spend a few minutes thinking about what I explained above AND Pop's post above. I know for a fact that the K&N elements are typically not very large for our trucks, especially in comparison to a lot of their competitor's elements. That means that the only way the K&N elements can flow more air than their larger competitors' elements is by having larger openings as was confirmed in the air filter study above. Allowing fine dust partciles to flow through these larger openings in a K&N on our turbo diesels is a sure way to ingest more dirt (silica) into the engine, and in the meantime, you'll be mildly sandblasting your turbo wheel every mile you drive... might not show any issues in a year or two, but they will definitely show up, and not until AFTER the damage has been done.

If you want to prematurely damage your turbo wheel (which spins up to 30,000 rpm) and create premature wear in your engine, that is certainly your prerogative, but it is not a wise decision by any means.

 

Interesting read. With that said there are still a ton of variables, how well said filter seals to corresponding box, etc...

He states that the worst performing filter only reduced flow by .25psi over no filter at all, suprised me!

He also states that there is a direct link between airflow and how much it can filter. I don't think this is entirely true. If a filter has more pleats or more surface area, it can flow more without letting more through.

Near the bottom he shows pics of what filters did the best. Every filter let some through including the Napa. I guess the question is how much is acceptable to you.

Filtration Testing for Amsoil, K&N, Napa, Jackson Racing, Baldwin, and Mazda air filters on a Miata

He states he doesn't like the hassle of having to service and clean the cotton gaze filters and prefers paper, like a throw away. I myself prefer the cleanable style and for $50 for a reusable K&N or $55 @ my local NAPA store for a gold paper its a no brainer.

 

NAPA will rape you. Order from Riffraff Diesel instead.

 

20 years ago when the unleaded gasoline was still in the developement stage, the intake valves on a lot of fuel injected cars would get a HUGE buildup of carbon on the back side of the intake valves.
A lot of them would look like a bee's hind leg loaded with black pollen.
What would happen is the carbon would absorb the fuel being injected like a sponge instead of allowing it to pass into the combustion chamber, resulting in a huge flat spot on acceloration.
It was called "tip in hesitation" at the time.
The cure, and it was temporary, was to remove the intake manifold and, cylinder by cylinder, rotate the crankshaft to TDC, valves closed for that cylinder.
Then take a device similar to a sandblaster, but loaded with walnut shells and clean out the intake port.
Rotate the crankshaft to the next cylinder valves closed and repeat until all the intake valves were cleaned out.
.
That procedure didn't last very long because it was obvious that it was the fuel causing the issue and the formula was changed.
Nowadays you pull and intake manifold and all the valves look brand new.

 

K&N filters do not pass Cummins specs for dirt removal. I used to run them in everything untill I ran across that fact about 12 years ago. Now I won't use them in anything. The point of a filter is to catch dirt and I want the one that catches the most.

 

I would suggest that someone, who has already made up their mind and made their purchase, does not wish to be confused or confronted with additional facts.

Jus' sayin'

Pop